Marvel's Transformers: Assemble and Roll Out is an animated Television movie and a crossover between Marvel Comics and the Transformers franchise. The film shares continuity with Iago PUC's version of Marvel's Spider-Man and also has elements of the 2010 computer-animated superhero television series Transformers: Prime.
When a small prototype of the Space Stone merges within the Allspark, the universes of the Marvel superheroes and the Transformers become linked to one another. Now Earth's superheroes (consisting of Spider-Man and his fellow Champions, the Avengers and the Guardians of the Galaxy) and the Autobots work together to stop a war between Earth's supervillains and the Decepticons which threatens their both realities and to defeat a new common enemy which emerged from the Space Stone and the Allspark.
In a Hydra space vessel, scientists under Red Skull's orders are making more experiments with weapons salvaged from the World War II era which still contain energies extracted from the Tesseract until their vessel is attacked and disabled by a Kree fleet under Ronan the Accuser's command. During the chaos, the vessel falls down to Earth and a fragment sample of the Tesseract is lost in space. In another side of the galaxy, a group of mercenaries were sent by Leland "Silas" Bishop searching for a treasure in the field where the Allspark crash-landed when it fell from orbit. During which, they are ambushed by Starscream and his pack of Decepticon clones and Energon Drones before the missing fragment of the Tesseract falls into the Allspark and merges with it, causing an explosion which makes the Tesseract disappear along with one of Starscream's Energon drones. With the Allspark and the Tesseract missing again in the universe, the two galaxies begin to merge into one same dimension. The missing Energon drone ends up teleported into an abandoned Kree lab and merges with a cloned Symbiote, resulting in the creation of a more barbarian life form and giving the drone a new mind of its own, on which it names itself the "Darkspine".
Meanwhile on Earth, Spider-Man and his fellow Champions (Tigra, Ant-Girl, Kid Arachnid, Ms. Marvel, Ghost Spider, Spider-Girl, Nova, Wave, Alpha Owl (through Edith) and Brawn) are chasing after Doctor Octopus and the remaining loyalists of the now-defunct Oscorp who had kidnapped Midtown High School teacher Anne Weying until they are attacked by out-of-control A.I.M. robots after Doctor Octopus' tentacles are corrupted by unstable Energon particles. During which, they are surprisingly aided in the fight by Autobots Bumblebee, Windblade and Grimlock, who were at the time investigating the whereabouts of Starscream's faction and managed to trace the Synthetic Energon which Doctor Octopus ingested to cure his paralysis. Meanwhile, Captain America, Iron Man, Black Panther, Black Widow and Hawkeye are investigating the wreckage on Red Skull's destroyed Hydra vessel after Captain Marvel and Thor prevent it from crash-landing into New Jersey while clashing with Red Skull and his agents. Just then, both groups are attacked by incoming Insecticons until the Avengers are aided by the Autobots Optimus Prime, Arcee, Jazz and Ironhide, who had arrived in the Avengers' dimension to try to uncover the source of the rampaging robots the Champions and the Autobots with Bumblebee fought against.
In the Autobot Space HQ, Ratchet and Jetfire are analyzing the remains of one of the corrupted Energon drones they fought in San Francisco and discover it is still connected to its creator. Just as the drone reanimates and attacks the pair, the Guardians of the Galaxy (Star-Lord, Gamora, Drax the Destroyer, Rocket Raccoon and Groot) arrive to destroy the creature and the Symbiote in it. Certain of the great threat they are about to face against, the assembled heroes and the Autobots gather in a former American military missile silo near Jasper, Nevada, with the salvaged robots. Through one of the drones, they learn of Darkspine's existence and his plans to ravage the universe with his army of Energon-powered Symbiotes. The heroes and Autobots agree to work together to defeat their fused enemy while also working to prevent their enemies, who are viewing each other as invaders, from annihilating each other in a battle which may result in collateral damage and civilian casualties.
They split in small groups, with some working on stopping the battles between the super-villains (including the forces of Hydra and Kree Empire and Doctor Octopus' faction) and Decepticons (both Megatron's forces and Starscream's faction), others work to uncover the source of what created Darkspine. After defeating a swarm of Symbiote/Energon drones, Ant-Man and Ant-Girl shrink themselves into one of them and extract its spark so that it can be used by Dr. Hank Pym and Ratchet for study. Tigra and Arcee infiltrate a hive of Insecticon drones and extract a fragment of the Tesseract and a Allspark shard before disabling the synthetic bomb programmed to expand the hive and destroy the city.
Deducing that Darkspine originated from the Tesseract fragment and the Allspark, the superheroes and the Autobots formulate a plan to locate and separate the fragment from the Allspark and use its energies to destroy Darkspine. Iron Man and Jetfire investigate the area from where the Allspark disappeared and scan its radiation before having a fight against Starscream and a squad of Sentinels he hijacked earlier. Captain Marvel and Windblade secure the destroyed Hydra vessel and retrieve the Tesseract-powered weapons after overcoming Ronan's Energon-powered Kree Sentries and a Symbiote-mutated Airachnid.
Under Gamora's suggestions, the Alliance splits in two groups to locate Darkspine on the planets he could possibly be. The superheroes make their way to Klyntar, the home-planet of the Symbiotes, while the Autobots set course to their former home planet on Cybertron. Just then, they discover that Klyntar and Cybertron have been merged together as one same planet, which will happen to their two Earths, destroying them both in the process unless they stop Darkspine. They also witness Doctor Octopus' crew, Ronan's Kree armada and Red Skull's Hydra forces as well as Megatron and Starscream's factions of Decepticons arriving to directly confront and destroy Darkspine once and for all.
The villain factions, however, view one another as Darkspine's minions and fight among themselves. The superheroes and Autobots work to stop the chaos while Spider-Man and Optimus are left to deal with Darkspine by themselves. Despite pursued by Doctor Octopus (who is rendered insane and aggressive due to the side effects of the Synthetic Energon) and Megatron, Spider-Man and Optimus manage to find and confront Darkspine, fighting him long enough for Bumblebee and Ant-Girl to reach the core of the Allspark and remove the Tesseract fragment, weakening Darkspine and allowing Spider-Man and Optimus to destroy their fused enemy and return Klyntar and Cybertron to their normal separation.
The villains and Decepticons are also returned to their dimensions with no memories of the incident. The superheroes and Autobots bid a honorable farewell before returning to their respective dimensions as well, with Optimus assuring Spider-Man that their universes will meet again one day. Sometime later, Peter and Mary Jane are making plans for their summer trip in Rio de Janeiro, Brazil, before discovering another Allspark shard which contains energies of the Tesseract and discover they can still contact the Autobots' dimension, on which they first come in contact with Bumblebee and Arcee.
- In a Mid-credit scene, Starscream is shown walking around a desert vowing revenge on the humans and Autobots before he bumps into a Energon-powered S.H.I.E.L.D. Quinjet, which transforms into a Cybertronian berserker and chases after him in rage.
- In a Post-Credit scene, Rocket is shown experimenting on a Allspark shard he collected during the battle until it accidentally converts one of his guns into a Energon Drone which begins calling him "daddy", much to his embarrassment and Groot's amusement.
- Robbie Daymond as Spider-Man / Peter Parker
- Peter Cullen as Optimus Prime
- Ashley Johnson as Tigra / Mary Jane Watson
- Roger Craig Smith as Captain America / Steve Rogers, Jetfire
- Mick Wingert as Iron Man / Tony Stark
- Josh Keaton as Bumblebee
- Tara Strong as the Alpha Owl / Carlie Cooper
- Jessica DiCicco as Ant-Girl / Cassie Lang
- Laura Bailey as Ghost Spider / Gwen Stacy, Black Widow / Natasha Romanoff
- Scott Porter as Star-Lord / Peter Quill
- Sumalee Montano as Arcee, F.R.I.D.A.Y., Gamora, Yuri Watanabe
- Jennifer Hale as Captain Marvel / Carol Danvers
- James Arnold Taylor as Ant-Man / Scott Lang, Jazz
- Mae Whitman as Wave / Teresa Parker
- Nadji Jeter as Kid Arachnid / Miles Morales
- Kathreen Khavari as Ms. Marvel / Kamala Khan
- Jack DeSena as Nova / Sam Alexander
- Melanie Minichino as Spider-Girl / Anya Corazon
- Travis Willingham as Thor, Grimlock
- Troy Baker as Hawkeye / Clint Barton
- Eric Bauza as Brawn / Amadeus Cho, Swoop
- Jim Meskimen as Ratchet, Dr. Hank Pym
- James C. Mathis III as Black Panther / T'Challa
- Kevin Michael Richardson as Ironhide, Groot
- Erica Lindbeck as Windblade, Anne Weying
- Trevor Devall as Rocket Raccoon, Rumble
- David Kaye as Vision / J.A.R.V.I.S.
- Fred Tatasciore as Hulk / Bruce Banner, Megatron, Max Modell
- David Sobolov as Drax the Destroyer, Breakdown
- Sam Riegel as Starscream
- Jason Spisak as Scorpion, Alistair Smythe,
- Scott Menville as Doctor Octopus / Otto Octavius
- Alistair Duncan as Vulture / Adrian Toomes
- Jonathan Adams as Ronan the Accuser
- Liam O'Brien as Red Skull
- Nika Futterman as Airachnid
- Steve Blum as the Darkspine, Shockwave, Abomination / Emil Blonsky
- Keith David as Soundwave
- See also: Transcript