The Scarlet Speedster Season Four

Season Four of The Scarlet Speedster is about Barry and his team dealing with a Meta-Human known as Cicada. It airs on FOX.

Created by Vince Gillian, David S. Goyer, and Geoff Johns.

2015-2016

Sources: JJLeee214. “The Flash: Season 4.” Arrow Fanon Wiki, arrow-fanon.wikia.com/wiki/The_Flash:_Season_4.

Cast Edit
Main Cast
 * Nicholas Hoult as Barry Allen / The Flash- 23/23
 * Laura Harrier as Fiona Webb- 23/23
 * Léa Seydoux as Caitlin Snow / Killer Frost- 20/23
 * Luke Pasqualino as Cisco Ramon / Vibe- 22/23
 * Corbin Belue as Wally West / Dark Flash- 14/23
 * Tessa Thompson as Nora-Allen Webb / Rewind- 19/23
 * Kevin Bacon as Earth-38 Dr. Harrison "Harry" Wells- 22/23
 * Morris Chestnut as Lieutenant  Desmond Webb- 23/23
 * James Franco as Sergeant Eddie Thawne/Booster Gold- 8/23

Recurring Cast Edit

 * Sharon Leal as Cecile Horton- 17/23
 * Ethan Hawke as Captain David Singh- 5/23


 * Violett Beane as Jesse Chambers Wells / Jesse Quick- 14/23
 * Sharif Atkins as Walter Steele Jr./ Mr. Terrific- 2/23
 * Charlie Hunnam as Oliver Queen / Green Arrow- 2/23
 * David Strathairn as Professor Martin Stein / Firestorm- 1/23 (Final Season)
 * Kaley Cuoco as Sara Drake / White Canary- 3/23
 * Franz Drameh as Jason Rutsch / Firestorm- 1/23 (Final season)
 * Blake Lively as Laurel Lance / Black Canary- 1/23
 * Tyler Hoechlin as Kal-El / Clark Kent / Superman- 2/23

Episodes
 * 1) "Welcome, Nora"- The season starts off with a flashback (forward)  to the future. In this future, we have a more hellish landscape in 2036. With tons of bodies of various DC faces. Such as Oliver's arrows in the ground stabbed into a leather hand, a mask of a certain bat themed vigilante covered in scars and some blood, and finally the old decayed mask of the Flash on a pike. So we zoom in away from these bodies to see a Meta-Human unlike any other. This one moves in a way different from others. Basically not running, but instead stealing the Speed Force to be in a temporary state of Flashtime to appear as a speedster. It has Nora in a hold on her neck. She then manages to grab the Speed they stole for enough time to run away and then arrives in Central City, 2014. This is when we have a time skip to 1 year later. Where Fiona, Cisco, and Caitlin support Barry at some crimes around the city. Eddie comes in as support, taking down some criminals. Nora also saves some people and Barry has been giving her the silent treatment. A few more crimes later and Nora is sick of it. Starting to lash out at why Barry is dismissing what she said at the Webb House. Barry tells her that she needs proof if he is going to listen to her and having Fiona's jacket is not convincing him. She runs away from S.T.A.R labs in frustration. Linda is convinced, however after everything with the Thinker as well as Thawne, Barry is feeling that this is some trick or secret plan. Meanwhile, Cisco has now been helping Caitlin get Killer Frost back and they have been making some headway on that. Caitlin has also been improving Cisco's abilities in order to have him unlock the ability to freeze speedsters in place just like the Collectors. Desmond Webb has finally pushed for Barry to get his job back with the help of Fiona. Now Desmond has been staying at his home raising the baby. However it has been hard for him to balance this with both his job and Team Flash. Meanwhile, Fiona has been secretly speaking with her daughter. Finding out info on a "speedster" much faster than she is that has taken down most of the world and was caused by her. This causes Barry to be even more untrusting.
 * 2) "Chance"- Fiona meets a renowned quantum physics genius named Wyatt Infantino on her quest to find Wally, who helps track him down, but cannot find a trace of him anywhere on the planet. Back at STAR Labs, Cisco loses hope and says there is no possible way to get back Barry's speed fully, as they can't duplicate the particle accelerator reaction, as it would kill him for sure. The Rogues prove a big threat to Booster Gold and Nora when The Mist poisons him and they successfully steal a priceless diamond from the museum. Wyatt Infantino believes that Wally West may be outside of team. Fiona invites Wyatt to join Team Flash. Meanwhile, a businessman and genius scientist named David Hersch holds a press conference, where he discusses his opinions against speedsters and opts for speedster regulation.
 * 3) "The Return Of Captain Cold"- Barry remains with half of his speed and not even Harrison Wells or John Fox from the future can not even help him. After a daring attempt to get back his speed, Barry is then approached by the unnerving revelation that the Speed Force might eventually be  completely ripped out of his body. Meanwhile, Leonard Snart AKA Captain Cold (Mike Vogel), mysteriously returns to Central City without the aid of the Waverider and despite being dead which is why Barry and Cisco want to bring him in. Fiona conspires that Captain Cold's return has to do with Wally's revival. Cynthia tries to have a normal day as a couple with Cisco, but their Team Flash work gets in the way. The Flash, Rewind (Nora), Eddie and Vibe meet up with Leonard and question him on why he returned. However, Captain Cold blasts The Flash and Rewind with his Cold gun and manages to subdue Vibe, saying that "he never reveals any of his secrets". Caitlin begins to think that Alex went rouge, but Earth-38 Dr. Wells and John both believe that this version of Captain Cold is an anomaly when John's time manipulation machine suddenly goes off. New detective Frank Curtis, becomes interested in the case and wants The Flash and his team to stay out of it. Captain Cold begins to murder all of his old gang contacts, and is nearly apprehended by Frank and the CCPD Task-force. Frank reveals that he lost someone close to him because of Leonard, and Leonard nearly kills him until The Flash speeds him out of the way. The Flash warns Captain Cold to stand down, and that they were friends. Leonard calls Flash weak and reveals that he has a bomb hidden in four main parts of the city, so John, Cisco, Caitlin, and Dr. Wells locate the bomb. Rewind, Vibe, Gypsy, and Jessie Quick take down Captain Cold's gang, and The Flash pins Leonard to the wall. The Flash vibrates his hand intending to kill Leonard, but Cold taunts Flash saying that he doesn't kill and he is wasting his time. Cold then escapes, as Flash looks on angry. In the end, Cisco and Cynthia enjoy a romantic evening, John decides to go back to Earth-Three and Captain Cold breaks into Iron Heights, killing multiple guards and frees his sister Lisa Snart, who claims that there will be an "army of Rouges" to take back Central City from the heroes.
 * 4) "Army Of Rouges"-   After the last battle against Captain Cold, Team Flash suffers a great failure and Wally feels responsible for letting Leonard go. Captain Cold successfully broke Lisa AKA Golden Glider out of prison, and begins committing various crimes. Captain Cold begins to think about reforming the Rouges, but this time as a team of criminals. Leonard recruits Earth-12 Iris West, who has been trying to live a normal life, but Captain Cold persuades Patty to become Doctor Light again so he can get his revenge on The Flash. Golden Glider recruits Owen Mercer AKA Boomerang . With the Rouges fully assembled, they begin wrecking havoc in the city. Meanwhile, Fiona interviews David Hersch for the Picture News and learns of his newfound hate against speedsters and eagerness to ban them. Tracy visits S.T.A.R Labs telling the team that one of her colleague's son has gone missing and Caitlin begins tracking them down. Finding a location, The Flash, Rewind and Jessie Quick head to an abandoned building where suddenly they are attacked by Cobalt Blue. He weakens everyone using his talisman heart, while Jessie manages to save Jefferson Pierce from Lisa's weapon forcing her to escape. Cobalt Blue continues savagely beating up Flash until he nearly kills him. Captain Cold orders Toy Man to plant explosives in the area, as the whole building explodes. They manage to escape, and head back to S.T.A.R Labs where Cisco privately tells Wally that if he continues to fight crime it could burn out his speed permanently, to which Caitlin adds more electric armored padding on the suit to protect him from talisman rays. Cisco, Caitlin and Jefferson finally get a lead on Anissa Pierces' whereabouts which is why Desmond leads the CCPD Task-force to the location followed by The Flash, Nora,, Vibe and Gypsy who take a group of criminals. The Flash engages Cobalt Blue in a heated battle once again, with Blue beating Flash up again. Rewind then tackles Cobalt Blue continuously punching him in the face, until he throws Blue around the wall as Rewind throws lightning knocking him out. The CCPD task-force begins defeating more thugs, as Captain Cold, Golden Glider and Boomerang escape from captivity leaving Cobalt Blue to be arrested. Later, Jefferson reunites with Anissa who promises to Barry that he will keep his identity a secret and they head back to Freeland. Tracy decides to be a part time member of Team Flash suggested by Dr. Hamilton Earth-38, who believes that she needs to have a normal life. In the end, Blue is bailed out of prison by an unknown person and begins walking outside. He then speeds to an alley, where he sees a group of thugs. A man dressed as The Flash then brutally murders Cobalt Blue in front of the thugs, and he tells them to report that Flash caused the murders as he smiles evilly and speeds off.
 * 5) "Potentiate"- After saving the city from the hands of the Rouges, and causing them  to retreat, Team Flash  finds themselves confronting rich businessman and famous scientist, David Hertsch, who wants to buy STAR Labs and reform it to promote his anti-speedster movement  and to create a new company, Hertsch Sciences Knowing that they run a speedster operation, Cisco plans to make the Cortex just like the Time Vault, secluding it and hiding it within the building. Cisco is called and chosen to represent STAR Labs and Team Flash. Cisco reluctantly accepts the offer to buy STAR Labs from David Hertsch , who grants Team Flash 2 billion dollars for research and future projects, but Earth-38 Dr. Wells begins to think that there is something more to Hersch "than meets the eye". Hertsch's team moves in to reform the lab while Cisco is confronted with the possibility of having to relocate the base of Team Flash. . Meanwhile, Detective Frank Curtis reveals to Desmond that "The Flash" was spotted killing Cobalt Blue in front of a gang, which makes him want to investigate the perpetrator. Desmond and the CCPD Task-force track down the Meta-Human, who easily takes down the police, severely injuring Frank. The man then kidnaps Desmond, and he wakes up at an abandoned building where the man reveals himself to be Clifford Zmeck, someone who believes that The Flash should fall. While he isn't looking, Desmond manages to contact Caitlin and reveals where he is. Fiona sends Rewind and Gypsy on the field to rescue him. Arriving at the location, Rewind phases into the building, taking down guards as Gypsy breaches in and successfully saves Desmond. She then speeds him out, and then zooms back inside. Clifford attacks Gypsy, when she tries to blast him with concentrated vibe energy, while Rewind engages in a high speeding fight with him. Clifford subdues , and nearly kills her until Eddie and Caitlin arrive with a weapon that takes away his powers. He then escapes, by throwing a smoke grenade. Fiona asks Caitlin to be her maid of honor. In the end, Clifford meets up with Faroq, and The Mist who also want revenge on The Flash for their previous defeats, just as a female scientist is revealed to have been watching everything that goes on in S.T.A.R Labs.
 * 6) "Angles In Time"- Hertsch Sciences has taken over S.T.A.R Labs. Team Flash is forced to move out and find a new base. Using the 2 billion dollars, Cisco pays Hertsch to let them have the Cortex for a week. Instead, Cisco and Wyatt team up to take notes and create blueprints of the Cortex so they can use the money to replicate and rebuild somewhere else. Meanwhile, Caitlin and Earth-Thirty eight Harrison come up with a last-resort plan to find someone who could  be able to fully get Barry's speed back and suggest the possibility of getting Darwin Elias (Johnny Galecki ), from the timeline before he was killed by Reverse-Flash  and see if him, a genius, can figure it out. Nora agrees to take this courageous step, running so fast that he travels to the year 1994. Clifford who now calls himself Major Force has been working with Faroq, and The Mist causing various crime sprees and as well as abducting the mayors wife, and daughter. Barry becomes desperate to stop them and Desmond tries to call off the Task-Force against The Flash, but to no avail. He, Cisco, Fiona and Caitlin advise Barry to be careful while going after them. The Flash, Booster Gold, and Vibe go after the trio and Barry confronts Faroq in an epic fight. Dark Flash is able to subdue Barry. Eddie fights The Mist who has grown massively since his last appearance, and severely injures him. Vibe goes to safe the mayors daughter and wife, but Dark Flash defeats Vibe knocking him out. The trio escape, but The Flash still manages to save the mayor's family. While in 1994, Fiona finds a version of Darwin Elias who worked for Dr. Harrison Wells before his death in 1998. Asking for his help for the year 2015, but Darwin doesn't listen. While Darwin is leaving the lab, he gets mugged and Nora as Rewind speeds in and takes down the thug which shocks Elias. Elias then decides to go with Nora, after learning that she is from the future and the daughter of Barry Allen. Nora runs so fast, she creates a portal to 2015 arriving with Darwin to S.T.A.R Labs as he looks around in awe. Barry tries to avoid looking at Darwin, realizing that the two never got a chance to mee each other before he died, which goes noticed by Time Remnant Darwin. Dark Flash and his squad of villains launch a war on the CCPD officers, forcing The Flash, Rewind, Vibe, Gypsy, and Booster Gold to help. The CCPD Task-Force attacks the team, with Barry evading the officers and angrily attacks him. Barry zooms and smashes him through buildings through the roof. The Flash then continues to punch Major Force. As Flash prepares to walk away, he nearly kills Barry until Frank shoots Clifford killing him instantly, who reveals that they should work together for now on. Mist continues to poison the others as Flash saves them. He then allows himself to get poisoned , however Barry uses the speed he has left and causes a powerful electric wave which explodes with Gypsy containing the blast with help from Vibe. As the police barge in they see that The Flash is gone, Back at S.T.A.R Labs, Barry passes out, and hits his head. When Barry wakes up, Cisco checks his vitals and learns that his powers are completely drained and that its like he is a normal human. Barry tries to use super speed, but he fails. Barry is then devastated that he may never get a chance to be The Flash again, but decides to give Time Remnant Darwin a chance and asks him to find a way to get his powers back. In the end, Time Remnant Darwin is then shocked, about the new task and decides to help Team Flash.
 * 7) "Genesis"- Upon a time remnant of the original Darwin Elias joining Team Flash, he gets to work. Cisco is halfway done in constructing the new Cortex, which is located secretly underground, dubbing it the Flashcave. Meanwhile, a new threat is created when HERTSCH Sciences tries to create a cloning system called Project Pollux. Time Remnant Darwin Elias realizes that this is the key to getting Barry's speed back. As he prepares to use Project Pollux, Barry may gain his speed back, but a new threat may result in the process.
 * 8) Crisis On Two Earths (Part Three)"- Oliver, Barry, Jason, Sara and Stein, wake up imprisoned on Earth-44 wearing power dampeners. Mobster Walter Steele plans to execute them, however, they are saved by Green Arrow (Malcolm Merlyn) and Ray Terrill. Ray and Malcolm take them to the headquarters of Lex Luthor's Justice League. They learn that the only way back to Earth-One is through a temporal gateway in a research facility, which Luthor plans to blow up to strand Deadeye on Earth-1. Oliver disguises himself as Deadeye to infiltrate the facility and discovers the doomsday device against parallel Earths is a militarized time-ship called Wellenreiter. Ray and Barry battle the Freedom Fighters' Red Tornado to stop it from destroying the gateway while the rest of the team enters the facility to reactivate its portal, during which Stein is shot and gravely wounded. On Earth-1, Thawne prepares to perform surgery on Clark to save Overman. Walter Jr. and Fiona try to stop him, but are captured.
 * 9) "Fallen"- The mid-season finale of Season 4 commences with a bang. Wally reveals himself to Team Flash and comes back, dawned in a new futuristic suit. Cisco dubs him The Dark Racer. Fiona is haunted by seeing her brother Wally in a whole new way and denies that he is the Wally West-Webb she knew, but Wally protests that he is different. Barry, back as The Flash, travels to the SpeedForce to ask for answers about Wally and Captain Cold, and they reveal that they are not responsible for the return of any of them, but someone is, and whoever they are, they are hell-bent on destroying the SpeedForce itself. Before Barry returns to the real-world, they tell Barry they are calling on him to defeat this threat, but they don't reveal who it is directly. As Dark Racer battles Team Flash, they soon learn that he is the real Wally West and not a doppelganger. Meanwhile, David Hersch is revealed to be a metahuman with the ability to siphon electricity and with a device that can make him immortal Cisco finally uses the money he gained from Hersch to create the Flash Ring for Barry. Dark Racer's SpeedForce ridding powers are revealed to be halfway powered by ice and he uses his energy blasts to trigger Killer Frost once more, who joins Dark Racer . Desmond Webb is kidnapped by the new evil duo, with his life on the line.
 * 10) "Dawn of the Rouges"- A month after the encounter with Cicada and Dark Racer, and losing Caitlin as she became Killer Frost again, Team Flash  is left stricken with the turning of Wally West, but even more threats lurk in the distance. Time Remnant Darwind has Tracy track down any sign of Killer Frost anywhere, in hopes of finding her and bringing her back safely but to no avail. Barry begins to blame himself for everything that has happened, and questions if he made the right choice in being The Flash and getting married to Fiona despite the risks. Cisco cheers up Barry and tells him that in the last four years, Central City has been protected by The Flash and his team and to not give up hope. He also mentions that what happened to Caitlin wasn't his fault and says that they will find her. Meanwhile, Fiona and Wyatt both get suspicious of what David Hertsch  is doing at HERTSCH Sciences and the two team up to sneak inside and investigate what's going on inside. They discover that he is a Meta-Human and has been working on a cerebreal looking project which was located on various shriveled up bodies on the floor.  The Rouges, lead by Captain Cold and Golden Glider, return to Central City and begin causing havoc. The duo target the CCPD twice, before Barry, Nora, Vibe, and Gypsy arrive and initially stop them. Leonard kidnaps Detective Curtis and a bunch of other police officers. Leonard sends a message to Star Labs, asking if he can meet with Barry privately. Barry suits up as The Flash and speeds off, and grabs Captain Cold speeding them off into another area. Meanwhile, Jessie has a heart to heart talk with Earth-38 Dr. Wells about their future, and she tells him that she feels like that ever since she left Earth-12 she has been missing her father, but tries to ignore it with Nora commenting that she feels like a burden since she isn't supposed to be born yet. Back in the woods, Barry tries to reconcile with Leonard, and asks him how he is alive again. Leonard laughs and says that he isn't the same Captain Cold that he knew, and blasts Flash with a ray of Cold energy from his improved gun. He then escapes, but not before revealing where the bombs are and saying that he knows that Killer Frost is back and is working with Dark Racer. Barry returns to S.T.A.R Labs, and leads the team along with Desmond and his squad to engage the Rouges. The Flash destroys the convoy of weapons and Vibe rescues the officers. Captain Cold manages to escape, but leaves his sister to get arrested by the police.
 * 11) "Cicada"- Fiona and Wyatt, after running into Hertsch and finding out that he is a metahuman, bring the news back to Team Flash. Barry then remembers that Hertsch was a name mentioned when Abra Kadabra was talking about people who impacted Barry's life. Barry goes to confront David Hertsch at his office in HERTSCH Sciences. There, he learns about Hertsch's metahuman powers as superhuman intelligence and his intentions to destroy the SpeedForce. Hertsch, who already knew that Barry was The Flash, said that he was affected by the particle accelerator and given immortality, enhanced memory, and the ability to control Speed Force energy. He was able to figure that the Flash was Barry Allen just by looking at the Flash's face, with the mask on. Hertsch was interested in other metahumans and studied Barry Allen for years. With his deduction skills, Hertsch predicted Flashpoint and The Thinker. With his deduction skills, Hertsch predicted that Barry Allen would lead a legacy of speedsters that ultimately ended in tyranny, the destruction of the city, and the death of his beloved family. In efforts to protect his family, Hertsch deduced that now would be the perfect time to enact his plan; the destruction of the SpeedForce and getting rid of all speedsters. Learning of Hertsch, Barry and Team Flash find a new threat in him and at the end of the episode, arrest him with ease.
 * 12) "Total"- Team Flash focus all of their attention on taking down Cicada, who they learn has been working with Wally to destroy the Speed Force, and even using Time Remnant Captain Cold as a distraction. Polux returns to Central City and begins killing various Wells Corp employees . Realizing that he needs all the help he can get, Barry calls John Diggle for help as A.R.G.U.S has anti-Speedster weapons. Using an algorithm to track Polux, The Flash and A.R.G.U.S join forces and arrive to the area where Polux shows up. He taunts Diggle saying that he could demolish his agents in less than a second. The Flash demands Polux to hand over the atomic weapon, but he refuses and instead engages Barry in a fight. The two clash and have a major battle across the city. Suddenly, Cicada creates a portal and takes Polux away when Barry begins winning but not before they subdue him. Angry that Polux got away, Barry becomes determined to defeat his clone and has Cisco track down Cicada's secret hideout. This time, Team Flash join together with A.R.G.U.S and Gypsy breaches them to the hideout where they bring the fight to Cicada's team. While The Flash battles Polux, Rewind, Vibe and Jessie Quick attack Cicada but he manages to subdue them. Polux nearly beats Barry to a bloody pulp, until Diggle activates a cold gun device which weakens him. Barry manages to subdue him, and allows Diggle to lock him up in an ARGUS facility. In the end, while Barry and Nora are training a breach opens up in the pipeline room. As the Speedsters including Cisco and Cynthia also breach into the room with Fiona, Earth-Thirty Eight Dr. Wells, and Wyatt running in as they see an injured John Fox when he falls on the ground. Before he gets knocked out, he mentions someone known as "Humanite" ending in a cliffhanger.
 * 13) "War Of Earth-Three"- John recovers from his injuries from his fight with Humanite, who reveals that he is John's arch-nemesis on Earth-3. John explains that Ultra Humanite caused a major war that killed many people on his Earth. Fiona asks to talk to Barry in private, with her stating the fact that the team still have haven't had time to track down Killer Frost and manage to protect Central City with Cicada still on the loose which would be hard to do without him there. Barry reassures her that he won't be gone too long and announces to the team that he intends to go with John to Earth-3. Barry kisses Fiona and asks her to have faith in him and to stay put until he comes back. Barry, Wyatt, Cisco, Gypsy, Nora, and Darwin  go to Earth-3 when Earth-Three Flash creates a breach as they speed into it. Barry witnesses a potential future where he is in prison, Fiona getting pregnant, and a female Speedster hero protecting her city. Arriving on Earth-Three, Fox takes the team to his headquarters where they discover that his team were captured and murdered by Ultra Humanite and his enforcers, "Operative" and Ice who rule Central City with an iron fist. Ultra Humanite discovers that Fox is back on Earth-3 so he sends his gorillas to kill Rochelle Barnes, who was a former superhero, to which the team agree to save her. The Flash, Vibe, Gypsy, Rewind, and Earth-Three Flash arrive to Barnes' loft where they engage the gorillas. Operative and Ice arrive and start attacking The Flash. The Flash gets caught off guard when he sees that Operative is Patty Spivot's doppelganger from Earth-3, which allows Ultra Humanite to savagely defeat him. He then escapes, bringing Barry to his lab. Cisco and Wyatt comes up with a risky plan that might be able to save Barry. The Flash awakens in a Speed dampener cage where he begins to get weak. Humanite then states that his gorilla vessel has been failing for many years now, but he believes that if he can have Barry's body he will become unstoppable because of his Meta-Human DNA. Barry then swears that he will defeat him, but Humanite laughs and says that Speedsters never learn. The team engage the soldiers from the outside and Gypsy manages to defeat Operative in hand to hand combat. Vibe and Rewind double team Ice as Vibe throws a concentrated vibe blast at her, while Rewind throws solar lighting at her which knocks out Ice. Time Remnant Darwin  and Wyatt then break into the lab and rescue Barry and his other captives. Ultra Humanite arrives preparing to kill them, until Earth-Three Flash bursts through the door engaging in a high speeding fight with him. Humanite then begins to gain the upper hand, until The Flash and Rewind fire their full power speed force energy which defeats him. Fox has Humanite sent to a Meta-Human prison. The team, arriving with Earth-Three John head back to Earth-One where they celebrate the fact that they won. In the end, Cicada opens a breach into Earth-Three and recruits Humanite saying that Team Flash are on Earth-One and together they are unstoppable as Humanite smiles.
 * 14) Fall Of Earth- Three- The Rogue War continues when Captain Cold and Golden Glider go against each other in a deadly Civil War with Central City caught in the middle. Nora has been kidnapped by Team Cold (dubbed by Cisco), and Jesse has been kidnapped by Team Gold (dubbed by Cisco). Barry and Vibe/Gypsy split up to rescue the 2 young speedsters. In the midst of the battle, it is revealed that Cicada and Dark Flash have planned this, with Cicada using his psionic abilities to control the minds of Team Gold and distract Barry. Cicada and Dark Flash begin building a device to destroy the SpeedForce, and it is confirmed that their base of operations is the Vanishing Point. Cicada's method of reviving people back from the dead is brought to light, Captain Cold and Wally are both time remnants. It's revealed that Dark Flash and the Cicada have access to time travel, who traveled back in time to steal half of Barry's speed during the Season 3 finale. Flashbacks are seen with Cicada recruiting Wally and Leonard, manipulating Wally. Meanwhile, the Vibe enlists the help of Green Arrow and Superman to take down the Rogues once and for all.
 * 15) "The Great Speedster Hunt"- After the big battle, the Rogues have been put in HERTSCH Sciences, the Pipeline, much to the dismay of Team Flash. The device is halfway done and Dark Flash is tasked by the Cicada to go out and hunt the other speedsters. As they begin their ultimate crusade they've been planning, Dark Flash goes out to hunt down Rewind, Jesse Quick, and Barry Allen in order to gain their SpeedForce energy to give the device the proper energy it needs. As the Flashcave is invaded by Cicada and Dark Flash, Fiona realizes that maybe Wally might not be in control of his actions. Caitlin takes part in the hunt and proves to be most useful in catching the other members. The Flash and his team manage to escape, while Cicada angrily decides to let them leave.
 * 16) "The Flash Family"- Barry, desperate to stop the Cicada, assembles Rewind, Jesse Quick, John Fox, and finds an ally in the Black Flash, who is sent by the SpeedForce to defend it from Cicada. Gypsy sends a speedster from Earth-38, the Accelerated Man, to help. A full-on attack is led on HERTSCH Sciences, but they realize that Pollux is back. When Cicada and Dark Flash escape back to the Vanishing Point, The Legends are contacted by Barry's team, and the Waverider takes them to the Vanishing Point, where they encounter their enemies and try to defeat them and end it, but realize they've walked into a trap, betrayed by Killer Frost.
 * 17) "Coming Together"- The Flash Family has found themselves kidnapped by Cicada, who plans to make sure that their SpeedForce energy comes together with the device as one so it has the proper fuel to activate. Black Flash manages to escape and ditches the team. It is revealed that the device will be powered by Dark Flash's energy blasts, as they have the ability to completely destroy the SpeedForce if built up and put into proper use and form. Cicada explains his backstory to the speedsters before activating the Coming Together Process, with results in a huge drain of their speed. Vibe and Gypsy realize that the speedsters are in trouble and go to the Vanishing Point to rescue them with the help of the Legends. It's up to the two of them to rescue their friends and save the SpeedForce, but confront Pollux, who has joined The Cicada. The Legends, Vibe and Gypsy manage to defeat Polux by injecting him with nanites that disable his speed.
 * 18) "Crisis Incoming"- The Convergence Process has been complete, and the speedsters manage to escape the lair because of Vibe and Gypsy, but they prove unsuccessful in stopping the device from being built.Wally is revealed to not be mind-controlled, but pulled out of the timeline by a time machine that Hertsch built using his immortality. Barry begins to have nightmares and Cisco has vibes of the future, which affects Nora's future where Cicada succeeds and the SpeedForce is destroyed, but realizes that since the SpeedForce is beyond time, if it is gone, then that means throughout all time, the SpeedForce won't be there, meaning that Barry wouldn't just lose speed, but because of a time loop, he may never get his powers.  Cisco also gets a revelation to recruit someone from another universe, who is smarter than Hertshc to help him counter Hertsch's plan. Julian returns, almost finished making a cure for Killer Frost that won't be countered by Dark Flash's blasts. Later, Team Flash builds a device to ampily Cisco's vibing and Cisco vibes every single human in the entire multiverse. He doesn't find any human smarter than Hertsch and the team learns that Hertsch is the smartest man in the multiverse. Cisco then vibes the future, where he sees something that causes him to try to kill Barry. At the end, Nora leaves Team Flash to see if her future changed. Meanwhile, the episode is told in Cicada's perspective too and shows his hidden plans and what he's been doing.
 * 19) "The End Of The Speedforce"- Barry loses confidence and goes to the SpeedForce to let them know that he can't do the job and save the SpeedForce. They then boost his priorities to save it by putting Barry in a fake reality where Cicada has succeeded. Barry is given 24 hours to survive without speed and if he doesn't make it, he will die in real life. As Barry fights for his life in this potential future, Team Flash back at home must defend the Flashcave from an attack by Killer Frost and Dark Flash. Julian tries to put the new cure into Caitlin, but fails. Meanwhile, Nora arrives at the Vanishing Point to join Cicada's team and destroy all speedsters. The end of the episode reveals the future that Hertsch tries to prevent; The Flash tries to save the Earth from a crisis. But, Hertsch's family become caught in the middle of the war and are ultimately killed. Hertsch time traveled to the year 2012 and formed his company in order to find the right moment to become The Flash's enemy three years later.
 * 20) "Enter Flashtime"- Dark Flash recruits every opponent that Barry has ever faced such as Abra Kadabra and the Rouges. When Barry attempts to stop them from stealing a bomb at a nuclear plant, he enters a form of super speed known as Flashtime, where everything and everyone is frozen. Barry eventually gets help from several speedsters but is unable to undo flashtime and eventually involves members of his team into it. Everyone attempts to find a solution such as freezing it or sending it to another Earth. Unfortunately, these solutions are not viable. Eventually, Wells proposes the idea of obtaining the Quark Sphere from the Speed Force to send a lightning blast to the bomb, enough to disable it. Barry does so and throws the Sphere back into the Speed Force, saving Central City. John makes plans to retire. As Barry and Desmond are getting coffee, Eobard Thawne is brought back from the dead by an unknown individual.
 * 21) "Eobard Thawne, The Wise"-Eobard Thawne is brought back to life and has been revealed to been resurrected by Cicada. Barry and the rest of them are confused since Eobard was erased from existence when Flashpoint was erased and learn that Cicada found a way to save him by going back in time to stop the Black Flash from killing Eobard. Reverse Flash is saved and brought back, but learns of Cicada's true intentions to destroy the SpeedForce and all speedsters. Eobard tries to go after Cicada to kill him, but crosses paths with The Flash deciding that Eobard might have to die for his crimes. The two speedsters battle to the death, but eventually decide to team up in order to defeat Cicada and his team. Black Flash returns to get rid of Eobard for good, but eventually lets Eobard live so he can help Barry stop Cicada from destroying the SpeedForce. Meanwhile, Barry and Nora fight each other, with Nora saying that he caused her future to happen and that she made a mistake of saving him from The Thinker's bomb.
 * 22) "Hundred-to-One"- Surprisingly, Barry and Eobard find themselves teaming up to stop Cicada much to the dismay of Fiona.  As Barry and Eobard find themselves constantly start arguing over what to do to stop Cicada, Killer Frost finds herself getting more human and her desire to return becomes a little bigger. Reverse Flash does his best to get along with the team, but Cisco refuses to talk to him for everything that he has caused in their life. Meanwhile, Caitlin considers betraying Cicada  and tensions rise within the group and the cure seems to be working, rather taking a while. Rewind begins to feel guilty, missing her father and begins to contemplate whether she should betray Cicada. The team, along with Eobard attack the base and Nora reveals her deception, which allows The Flash to rescue Caitlin who subdue Dark Flash. In the end, Reverse-Flash reveals his deception and murders Nora. Just as her past history becomes erased. Nora makes Barry promise that he quits being a hero after stopping Cicada in order to spend more time with his family and avoid his death by the future Cicada along with the other heroes. Barry agrees to it, as she dies which makes him determined to stop Cicada.
 * 23) "Think Fast Think Faster"- Working together, Barry and Eobard subdue the Dark Flash when he attempts to kill Desmond and Fiona despite the two attempting to reason with him. As Eobard is trying his best to get along with everyone else, he suggests killing Wally which upsets everyone. Using a knife, Barry tries to get Wally to kill him only for Wally to hesitate at the last moment and free him from his alternate personality. Caitlin kills Cicada and uses Cecile's powers to send Barry into  A.I Devoe's mind when Devoe begins his enlightenment process. Barry discovers that the good Clifford Devoe still in there. The bad Devoe multiplies himself forcing Barry and the good Devoe to fight him off. Barry wakes up in the real world when the good Devoe sacrifices himself to save him realizing that Cicada's end game was bringing The Thinker back and Eobard kills Devoe when Devoe attempts to kill Cecile. Barry, Cisco, Eddie, Eobard, and Darwin shield everyone from Devoe's falling satellites and Caitlin helps him destroy the last one. Harry's brain resets because of Caitlin and decides to return to his Earth to be with his daughter. Caitlin leaves to spend some time alone to think about everything that has happened. Thawne leaves promising to kill Barry some other time. Later, Fiona is revealed to be pregnant with Nora and Barry decides to have a normal life with her as a promise to his daughter from the future before she perished. The team is then left to protect Central City.