- Iron Man (Tony Stark)
- The Hulk (Bruce Banner)
- Thor (Thor Odinson)
- Ant-Man (Hank Pym)
- Wasp (Janet Van Dyne)
- Leonard Samson
- Balder (Balder Odinson)
- Jane Foster
- Hawkeye (Clint Barton)
- Pepper Potts
- A.I.M. (First appearance)
- Scientist Supreme (First appearance)
- Lucia von Bardas (First appearance)
- Wrecker (Dirk Garthwaite)
- Zzzax (First appearance)
- Absorbing Man (Crusher Creel)
- Mad Thinker
- Blizzard (Donnie Gill) (First appearance)
- Grim Reaper (Eric Williams)
- Baron Strucker (Wolfgang von Strucker)
- Arnim Zola
- Constrictor (Frank Payne) (First appearance)
- Grey Gargoyle (Paul Duval)
- Red Ghost (Ivan Kragoff) & his Super-Apes (First appearance)
- Mandrill (Jerome Beechman)
- Whirlwind (Dave Cannon)
- Griffin (John Horton) (First appearance)
- Mandarin (First appearance)
- Living Laser (Arthur Parks) (First appearance)
- Whiplash (First appearance)
- Chemistro (Curtis Carr) (First appearance)
- King Cobra (Klaus Voorhees) (First appearance)
- Crimson Dynamo (Ivan Vanko)
- Wendigo (Paul Cartier) (First appearance)
- Purple Man (Zebediah Killgrave) (First appearance)
- Baron Zemo (Heinrich Zemo) (First appearance)
- Graviton (Franklin Hall)
- The Leader (Samuel Sterns)
- Abomination (Emil Blonsky)
- Doctor Doom (Victor von Doom) (Mentioned)
Races and Species:
- Iron Man Armor MK VI
- Crimson Dynamo Armor Mark I
- Grim Reaper's Scythe
- Zola's Robotic Body
- Alchemy Gun
- Wasp's Suit
- Hawkeye's Suit
- Ant-Man's Helmet
- Pym Particles
- Ant-Man's Suit
- S.H.I.E.L.D. Helicarrier (Destruction)
Iron Man is in Slovakia breaking up an arms deal between A.I.M. and von Bardas, involving Stark's technology. He captures the A.I.M. agents and hauls them to The Vault, but lets von Bardas go free.
Inside The Cube, Samson is talking to Bruce Banner, and Banner tries to warn him that The Cube is not a prison, it's a gamma bomb just waiting to go off.
Atop a tall building in New York, Thor stands looking out over the city when Balder appears, and tries once again to convince Thor to come back to Asgard at the behest of Odin. Thor again declines, when they hear a crash far below. Jane Foster is tending to one of the accident victims, when another car hits the wreck as well and is about to crash into Jane when Thor slams into it from above. Jane thanks him, then asks him if he's following her, and he embarrasedly tells her that yes he is, because he finds her intriguing.
Iron Man drops the A.I.M. guys off at The Vault where he is greeting by Jimmy Woo, who wants to talk to him about security. Iron Man tells him to make an appointment with Pepper, and that whatever it is, it can wait one day.
Aboard the S.H.I.E.L.D. Helicarrier inside The Big House, Hank Pym has shrunk himself down and is talking to the Mad Thinker about the conversation he had with Whirlwind. The Mad Thinker tells him that it's in the air, and inevitable. Elsewhere aboard the carrier, Maria Hill and the Wasp are talking when the Black Widow bumps through them without saying a word to either one. When Janet asks who that was, Maria tells her that it's classified.
Just then, the power starts flickering all over the Helicarrier. Inside The Vault, the power is flickering as well, and then the energy goes completely down, letting the prisoners free. The same thing is happening inside The Cube, and in The Big House, Hank is writing down some notes, when he notices the energy barrier disappear, freeing the prisoners in there, with him. Just then, The Big House begins growing back to normal size, crashing through the walls of the Helicarrier.
Inside The Cube, Leonard Samson is walking down a hallway, when he notices cracks beginning to form in the wall, and gamma radiation begins spilling through, until ultimately it explodes, exposing him to massive doses of gamma radiation.
Onboard the Helicarrier, Nick Fury is trying to maintain control, when Quartermain informs him that reports are coming in of failures at both The Vault and The Cube, and that there is no communication with The Big House. Inside The Big House, S.H.I.E.L.D. agents try to stop the villains from escaping but to no avail. Maria Hill and Wasp help free one of the agents from Constrictor, and Hill heads on to the bridge while Wasp goes to look for Ant-Man, who was in The Big House when the explosion happened.
Iron Man is flying back when Pepper calls to inform him that something is happening and the Helicarrier is going down, and JARVIS tells him that The Vault has stopped transmitting. In New York, Thor and Jane are sharing a table and talking, him telling her about his father Odin going into the Odinsleep. She tells him that he should be there with his family and that the world has gotten by okay without him for a while. Just then, there is an explosion and Thor flies to investigate.
Inside The Cube, Banner is freed from his restraints, but pinned down by rubble. Samson enters the room, and Bruce tells him that he's been exposed to radiation and they have to get him to a hospital. He needs Samson to help free him and The Hulk is their only chance. Samson goes to try and lift the block pinning Bruce, when he begins to exibit great strength and lifts the block fairly easily. Unfortunately, he is then struck from behind and knocked out by Zzzax.
Inside The Vault, the Living Laser breaks into the armory to help Chemistro and Whiplash get their gear. Just as Chemistro is getting the last of his things, he's knocked out by a freed Hawkeye.
Back in The Big House, the Wasp arrives and discovers that the entire place is totaled. Inside, Hank is fighting off both Mandrill and Cobra, while the robotic guards try to stop the Red Ghost, only to be destroyed by his Apes. The Griffin then attacks Ant-Man, knocking him several stories down. The Griffin is knocked out when a piece of debris crashes on him as the Helicarrier crashes into New York harbor.
Back in The Vault, Hawkeye is about to defeat Whiplash when Iron Man crashes through the wall and fires on them both. Iron Man is then crushed into a wall by an enormous block of ice, and he's attacked by both Blizzard and Living Laser. Laser slices off a piece of Stark's shoulder armor when the Crimson Dynamo grabs Stark by the head. Stark tells JARVIS to hack into the S.H.I.E.L.D. frequency and give the evacuation signal for them all to get out.
Aboard the Helicarrier, Hill arrives on the bridge and reports to Fury that The Big House is wide open and prisoners are reported loose on all levels and containment is at 0%. Fury tells her to forget about The Big House, and that their priority is The Raft. Inside the fourth prison, the prisoners are free as well, including Graviton.
Back in The Cube, Zzzax begins electrocuting Bruce, who then transforms into the Hulk. Inside the control room of The Cube, The Leader is watching events on the various monitors, and sends Absorbing Man and Abomination down to deal with The Hulk.
Jimmy Woo reports that all agents have cleared The Vault, as Iron Man is being crushed by Crimson Dynamo and frozen by Blizzard. Just then, two explosive arrows hit Dynamo, helping to free Tony. Iron Man then tells JARVIS to begin the self-destruct sequence for The Vault as he watches Hawkeye run off. Iron Man then makes his own escape from the prison and crashes outside and the building begins to explode.
Inside The Big House, Whirlwind is punching Ant-Man at superspeed, and threatens to find and kill the Wasp. Hank notices the Griffin below freeing himself and begin flying at him. Hank shrinks down and lets the Griffin slam into Whirlwind instead. He hooks back up with The Wasp and notes that he doesn't think it's over yet.
Inside The Cube, the Hulk is carrying Samson, trying to get clear, when he is attacked by Abomination and Absorbing Man. The Hulk pulls down some of the ceiling on them, giving him the chance to escape and get Samson to safety. Creel and Blonsky start to go after him, when the Leader tells them not to follow them. They have work to do right where they are.
Back in New York harbor, Nick Fury is leading a team over to investigate The Raft, leaving Hill as acting director. Just as they land aboard The Raft, the entire facility begins rising into the air, lifted there by Graviton. Fury orders his men to abort the mission and get out of there, when he is yanked off his feet and floated up into the air coming face-to-face with Graviton.