In the 6 part crossover event a new super villain team takes up the mantle of The Legion of Doom so Green Arrow, The Flash and The Legends come together to take on The Legion. After the first engagement between them causes massive collateral damage the new director of ARGUS, Rick Flagg brings forward an order for all vigilantes and powered heroes to come forward and be evaluated by the organization where they will decide whether or not the heroes may continue there activities. This divides the heroes with many, including Oliver, refusing to come forward. This puts him in direct confrontation with Barry and his allies who agree with the act. With The Legion of Doom still at large and our heroes divided this is an event that will shape the world forever and Leave its scars on everyone involved.
Grant Gustin As Barry Allen/The Flash
Carlos Valdes As Cisco Ramon/Vibe
Caity Lotz as Sara Lance/White Canary
Brandon Routh as Ray Palmer/The Atom
Echo Kullem as Curtis Holt/Mr Terrific
Nick Zano as Nate Haywood/Citizen Steel
Stephen Amell as Oliver Queen/Green Arrow
David Ramsey as John Diggle/Spartan
Dominic Purcell as Mick Rory/Heatwave
Megalyn Echikunwoke as Mari McCabe/Vixen
Franz Drameh as Jefferson Jackson/Firestorm
Victor Garber as Martin Stein/Firestorm
Emily Bett Rickards as Felecity Smoak/Overwatch
Tom Cavanagh as Harrison "H.R" Wells
Audrey Marie Anderson as Lyla Michaels
Brett Dalton as Rick Flagg
Legion of Doom
Liam McIntyre as Mark Mardon/Weather Wizard
Danielle Panabaker as Caitlin Snow/Killer Frost
Katie Cassidy as Laurel Lance/Black Siren
Manu Bennet as Slade Wilson/Deathstroke
Nick E. Tarabay as Digger Harkness/Captain Boomerang
Simon Merrells as Dr Simon Jones/Psimon
Todd Lasanse as Edward Clariss/The Rival
Part I: Behind The Mask
The episode opens on Lian Yu where Slade Wilson sits in his cells, suddenly he hears gusts of wind and screaming guards he is shocked when a mysterious figure phases through the door and introduces himself as The Rival he takes him and fellow prisoner Digger Harkness outside to a team of villains where he offers then a place on the team.
It cuts to Team Arrow on a mission in Star City against arms dealers, but ARGUS agents burst in lead by Lyla Michaels and tells them that the director needs to speak to them. Oliver and Diggle are shown the feed from the prison by ARGUS director Rick Flagg. Oliver is shocked and realises that he needs to go after Slade and The Rival. Flagg reluctantly agrees but only on the condition that a team of agents accompany them. Oliver contacts Team Flash and The Legends who all agree to help in the fight.
Cisco vibes Deathstrokes mask to a warehouse in an undisclosed location, while a decryption algorithm looks for possible locations the heroes take the time to catch up and socialize where Oliver admits his gratitude for there help but also his fear in going up against his most dangerous enemy. Barry lightens the mood by quoting Oliver from his rough training sessions.
The algorithm soon finds a location in Markovia and the team heads out to take on the team on The Waverider. Realizing it is a public area ARGUS advises caution to which they agree. Oliver and Barry enter first while the Legends wait outside to cover the perimeter. Oliver points an arrow at Slade's head and commands him to surrender. Slade does this and causes suspicion from Barry, it then cuts to outside where Black Siren uses her powers to attack the legends, this distracts Oliver and Barry so The Rival comes and frees Slade so that they can take on the heroes. Sara is in shock at Black Siren so is easily knocked out by her. The rest of the super villain team repels down from the buildings to take them on. With the heroes caught of guard and ill prepare they are nearly beaten, to cover their escape Weather Wizard causes hurricane and Black Siren uses her scream to topple a building. Barry unravels the hurricane and The Legends try to halt the buildings collapse. After the hurricane is gone the heroes look around to see the area destroyed with reported casualties coming in.
Part II: Makings Of A Hero
The episode opens with the heroes sitting traumatized on The Waverider looking back at there failure to beat the super villains who they have now dubbed as "The Legion of Doom". Lyla reports back to Flagg where he demands to meet with the heroes. The team arrives where Flagg reveals his real reasoning behind sending Lyla with them. He unveils the "Mask Order" an act that orders all vigilantes and meta humans to come forward to be registered by ARGUS where they will determine there strengths and weaknesses while also deciding whether or not they are fit to continue with their activities.
Flagg says they will be given 24 hours to come back in for evaluation. This immediately tears the team in two. Oliver does not trust the government given his past experiences with them, Stein agrees having been hunted by them in the past for his power with Jax being in immediate agreement, Mick realising that he will never pass decides to ignore the order and Mari feels offended at the need to prove herself in order to continue to be a hero. On the opposite spectrum Barry agree having seen the damage that he has caused with his powers saying that he could use some discipline, Cisco also agrees having lost his brother to Barry's unlimited power, while he no longer blames Barry he agrees the holding back people with that sort of power is in the world's best interest, Nate having been motivated by his grandfather trusts the government to realize where heroes are needed, Sara desperate to find her sisters counterpart see's agreeing with the order as her quickest means of starting and Curtis chooses not to put his career as Mr Terrific in jeprody so decide to agree to the order.
The next day Barry and his supporters leave for their evaluations while Barry urges Oliver coming with them not seeing something this serious as a choice, Oliver opposes saying to Barry that he has faced worse than Rick Flagg. While Barry arrives for his evaluation, Felicity gets a lead on the Legion so Oliver along with the team who chose not to fall in line go after them. They track Weather Wizard to a warehouse outside Star City, Oliver and Mari engage him and are able to beat him.
Back at ARGUS, Flagg is furious to here that the other heroes are in direct violation of the act so sends Barry to talk to him. Oliver and Mick are interrogating Weather Wizard to find out information on the Legion when Barry rushes in. Oliver is at first glad to see Barry and asks for his help in taking Mardon back to The Bunker. But Barry opposes him saying that he was foolish to go against Flag's orders while he expects such things from Mick. Oliver is shocked but has no time to react before the Legion barge in to reclaim Mardon. The Flash, Atom and Vixen hold of The Legion while Oliver, Diggle and Mick take Mardon out the back. ARGUS soldiers arrive at the scenes and repel them. Flagg leads them where he informs Oliver that he is under arrest. It then cuts to the Legion where they comment that it is "all going accord to Psimons plan".
Part III: The Hall of Justice
Oliver and his team arrive at the hanger he and Barry used during the Dominators war which has now been code named "The Hall of Justice" by Cisco, Barry offered it up to ARGUS and is now outfitted with advanced technology. Oliver is told by Flagg that he will not be detained but is he and is team are confined to the base until further notice. Oliver is frustrated at this fact but accepts it knowing the risk he took. Mardon is held in a meta human cell and is questioned by Barry and Cisco but he refuses to tell them anything.
Flagg is using all resources at ARGUS' disposal to find the Legion but is having very little luck. As a sign if good faith Oliver agrees to give Flagg an evaluation of Slade having been trained by him. Meanwhile, Ray feeling out of the loop is trying to hack into the mainframe to discover all the ARGUS has on the Legion, he is patched through to the interrogation of Mardon. Ray realizes that they are getting no where so asks for Ciscos help in using nanites that will force Mardon to tell the truth, Sara also helps given her experience in the field. They take the proposal to Flagg but he immediately shuts them down seeing it as untested and unethical. Oliver arrives and angrily protests to which Flagg threatens him with imprisonment if he continues to be a thorn in his side.
Barry and Cisco get out of the interrogation frustrated at having nothing, Barry runs into Oliver where he asks Oliver is he blames him in any way for his arrest, to which Oliver assures him that he knew the risks. Oliver takes him to Ray where they tell him about the nanites that could get the truth from Mardon, Barry however agrees with Flagg that it is untested. Oliver decides that he has had enough of waiting and decides to go against Flaggs orders and injects him with the nanites. Felicity arrives at the base as a distraction, she is able to use the bases servers to create a feed in the loop so that Oliver can use the nanites to find out the truth. Mick stands watch outside the cell,Oliver restrains Mardon and injects him with the nanites.
The nanites begin to work on Mardon but guards show up at the door where Mick tries to hold them off. Oliver tries to interrogate Mardon but he fights back and Mardon continues to utter the word "Psimon". Just as that happen Flagg and his men burst in and detain Oliver. Oliver and his team are put into a cell and confined. Barry visits him where he is frustrated with Oliver saying that it does to make them look good, Oliver asks Barry to search for any references to Psimon. Just as that happens though, The Legion attack the base distracting ARGUS agents, Oliver begs Barry to let them out and help but he refuses not wanting to make thing any worse.
It then cuts to Flagg who is walking through the base to Mardons cell where he is still delusional, Flagg then shuts of the camera feed to the room and throws a grenade into the cell killing him. The Legion shuts of the power to the base, unlocking Oliver's cell, he and his team make there way to lock up to retrieve there equipment. During the chaos Oliver gets his team to help Barry with the Legion while he goes to interrogate Mardon, only do find him dead with Flagg standing over him. When Oliver stares at him he see's a glow in his eyes which he recognizes, Oliver knocks him out and tells his team to meet him at the hanger. Mick agrees to stay behind to hold of ARGUS, Barry runs to Oliver where he pleads with him not to run. Oliver shoots Barry with a tranquilizer arrow and tells him to back off. Oliver takes of with his team to Lian Yu.
Part IV: Purgatory
ARGUS is desperately trying to reel in from the Legions most recent attack but have yet to realise that Oliver and his team have escaped. After Barry wakes up he speeds to Flagg to inform him of there escape. Oliver before he escaped sabotaged The Waveriders scanners so they were unable to track them. The team are curious as to why they are going to Lian Yu but Oliver explains that the glow in Flaggs eyes reminds him of the effects of a totem he encountered on Lian Yu and believes they can find some answers there.
Mari stays behind to pilot the plane while Oliver, Felicity, Jax and Stein parachute down too the island to investigate the cave systems looking for anything of interest. The team begin to have their own individual hallucinations of their worst fears. Oliver see's his father as he appeared when he shot himself telling him that he is a failure and is not worthy of being the Green Arrow, Felicity sees her former self when she was a rogue saying she has become pathetic and has thrown away her life, Stein see's his wife telling him that she has never shown her any love or compassion and that he is selfish, Jax See's Ronnie Raymond telling him that he is unworthy of the mantle of Firestorm and he will never live up to him.
Meanwhile, Barry and Cisco are looking for new ways of looking for the Legion but are coming up empty, Sara arrives and seems depressed, Barry inquiries and she tells him that seeing her sisters face on a criminal is haunting, Cisco realizes that he might be able to vibe Black Siren of Sara, this ends up successful and they discover that they are about to attack an ARGUS base that Lyla resides in, Barry takes his team ahead where Barry begins to inquire as to how The Rival is still alive, he ignores this and the two engage in a desperate battle, Sara takes on Black Siren who taunts he by saying that her Earth-1 counterpart was weak and ultimately deserved to die. Barry is ultimately able to best The Rival and Sara takes down Black Siren out of anger, Caitlin attacks Cisco out of pure anger he uses his powers to push her back against the wall knocking her out.
Back on the island the team one by one let go of their fears and arrive at a cavern formerly housed by Baron Reiter, shockingly soldiers begin to shoot at them, when they step out of the shadows it is revealed to be HIVE soldiers, Vixen uses her amulet and bests them, before Oliver can question them they suddenly die, they make there way into a chamber where a totem is held, Oliver touches it and begins to have hallucinations of a man buried under rubble holding his family it cuts to Barry searching for any references to the name Psimon and discovers Dr Simon Jones an extremist who was being hunted by ARGUS as a member of HIVE. It then cuts to Jones himself holding an amulet with his family's picture in it.
Part V: Pawns In A Larger Game
ARGUS has returned to the original site of the battle against The Legion in Markovia, Barry and his team have joined him there for a conference to unveil the Mask Order to the world. Oliver and his allies have also returned from Lian Yu and are also in Markovia, they seek to capture Flagg to see what he knows about Jones.
Martin is in the market getting supplies when he is attacked by the local police, Stein frantically calls to Oliver and Jax, they arrive there to find the area surrounded and are forced to attack them, Oliver injures many police officers, Mari causes a lot of damage with her powers and Firestorms abilities causes great fear in the city when it is broadcast all over the news. Flagg orders extra security at the conference and refuses to leave the base until after the conference. Flagg then receives a phone call from Jones telling them they need to talk.
Flagg meets Jones and he tells him that the attack on the market worked and people are more afraid of the heroes than ever. Barry asks Cisco if he has found any further information on Jones and tells him that he has come up empty on tracking him. The next day the conference begins where Flagg unveils the mask order and people seem to be pleased with it. Barry is quickly distracted however when Oliver and his allies in full costume arrive at the conference. Barry discretely runs outside and rallies his to meet them outside.
The two teams come face to face where Oliver tells Barry about everything he knows about Jones and tells him that the need to question Flagg on his involvement. Barry refuses to let him past saying that he has been reckless and that they need to go through the proper channels In order To get Jones, Oliver objects calling him a coward and nothing more than a lap dog. Barry apologizes but says he has to take them in. The teams engage in a massive fight where neither holds back. The fight eventually makes its way into the compound where the delegates witness them. Flagg begins an evacuation while Barry holds of Oliver's team.
Curtis uses his T-Spheres to protect anyone from Oliver, Ray stays with Flagg to protect him and Oliver eventually faces him. Oliver is eventually able to beat him and takes Flagg. Oliver orders the team to retreat but ultimately only him and Mari make it out. Nate catches up to them and tells them that he knows where Jones is and what his grudge is against him.