When Norman Osborn calls a meeting of the Cabal to discuss Asgard as a last holdout in his consolidation of power, Namor and Emma Frost are absent due to their betrayal during the events that unfolded in Utopia and replaced by Taskmaster. During the meeting, Victor Von Doom expresses his displeasure with Norman’s actions against Namor and accuses him of attempting to kill off members of the group not obedient to him. When Doom orders Osborn to bring Namor, he refuses and has Doom attacked by an unknown assailant, only to discover the body of Doom is actually a small swarm of robotic insects inside a Doombot. The insects proceed to attack the Cabal so Hood flees while Avengers Tower is evacuated with only Osborn remaining to fight off the swarm. When Norman’s Iron Patriot armor begins failing, Sentry arrives to destroy the swarm and later during a meeting with President Obama, Osborn attempts to get permission to invade Asgard under a claim that it poses a national security threat. The President feels the threat isn’t serious enough to warrant an invasion and orders Norman to stand down while Loki reminds Osborn on the events of Civil War, and that a tragedy similar to Stamford could be used to gain approval.
Victoria Hand then suggests that Osborn see a psychiatrist when she becomes concerned with his Green Goblin persona resurfacing, and the sky soon turns a strange color surrounded by the mysterious black Void. The tendrils from the Void start to damage New York City by wrecking buildings and while the Dark Avengers work on crowd control; Norman talks Sentry down and tells him this type of behavior will start to gain attention. Sentry then powers down but Norman realizes Lindy Reynolds may have caused his most recent meltdown so he sends Hawkeye (Bullseye) to kill Lindy who takes her for a helicopter ride, strangles her and then dumps her body in the ocean. When Sentry questions Hawkeye on Lindy’s whereabouts, Lester claims she committed suicide over the countryside by jumping out of the helicopter. Later when Volstagg leaves Asgard for an adventure on Earth, Loki and Norman see an opportunity to create a disaster by using Volstagg when he intervenes in a robbery. Norman sends the U-Foes which lead their fight to Soldier Field during a football game and Volstagg is bombarded by energy blasts which kill everyone in the stadium from the shockwave, causing the deaths of thousands of people.
Osborn and Loki watch in an astral form and declare Asgard will now be held responsible for the disaster, leading to an approval of a military attack. When Norman returns to his office, Victoria Hand enters and is told to assemble the Dark Avengers and members of the Initiative loyal to him to prepare for an assault on Asgard. Osborn is later seen trying to convince Ares to formulate a plan then discusses it with the rest of the team and states if they participate, they will be allowed to leave if they want. Meanwhile the President realizes Osborn is beyond government control while Loki informs Balder Midgard is preparing to assault Asgard and the battle begins when Sentry attacks first, followed by a massive assault led by Osborn. Elsewhere, Tony Stark and Maria Hill witness the attack so Donald Blake tells Hill to take Tony away as quickly as possible, then transforms into Thor, heading toward Osborn as quickly as possible but is attacked immediately by Sentry. Thor strikes Sentry but the attacks from Osborn and several Initiative agents manage to hurt Thor and incapacitated which Steve Rogers witnesses via news broadcast.
Meanwhile Ben Urich is arrested in Chicago for attempting to enter Soldier Field and Will Stern spots Urich, convincing the arresting officer to release Urich into his custody. The duo then leave for a local diner where they encounter Volstagg who’s heading back to Asgard to turn himself in, but Urich and Stern realize Osborn is attempting to shift public opinion so they convince Volstagg to accompany him on his way back to get his interview. During the siege, Daken turns on Osborn and supposedly kills him, but turns out it was a hallucination brought on by the Norns of Asgard. Diamondback sees the Dark Avengers engage Thor so she calls the Earth’s Mightiest Heroes while the Hood reveals the Norn Stones to his crime syndicate. Elsewhere, Living Laser assists H.A.M.M.E.R. agents in attacking Bucky Barnes and Commander Rogers and Bucky is corrupted until the Corruptor is incapacitated while Spider-Man and Spider-Woman are attacked by Mandrill and Griffin. As the battle for Asgard intensifies, Ares is engaged with Balder and learns about Osborn’s deception while Norman tells a battered Thor he’s under arrest but before he can take the God of Thunder into custody, Osborn is attacked with a rocket launcher by Hill.
Thor is taken to safety while Rogers delivers a speech to assembled members of the New Avengers, Young Avengers and Secret Warriors while Osborn dispatches Daken to find Hill in the town of Broxton, Oklahoma. Ares strikes Norman down and vows to kill him for lying, but is suddenly attacked by Sentry and is literally torn in half. Back in Brooklyn, the large group of heroes prepares to depart for Broxton and Bucky gives Steve his shield back while Jarvis gives him a briefcase to an unknown person. While enroute to Broxton, Urich, Stern and Volstagg reach roadblocks as they approach and spotted by H.A.M.M.E.R. agents so Volstagg exits the news van to engage them while Urich and Stern speed off to be caught moments later. While in custody, Stern fakes a seizure and knocks the guard unconscious so the duo free themselves and escape. When the Asgardians get word Volstagg has turned himself in, Knut warns the others of a prophecy while Loki believes him and escorts Knut to his bedroom where he’s murdered by the God of Mischief. Volstagg sees footage of Thor being beaten while in prison and the sheriff releases him, but Volstagg stops and sends a video out via webcam, to the world about the real events in Chicago.
Word spreads quickly and people everywhere begin questioning Osborn and his siege while Norman sends the Thunderbolts to infiltrate Asgard in order to steal a weapon from the armory. Spider-Man later frees Spider-Woman from Mandrill’s control and defeats both him and Griffin while Luke Cage assists Commander Rogers and Bucky Barnes in fighting off Living Laser. Nick Fury and his Secret Warriors also arrive to fend off H.A.M.M.E.R. agents and Rogers assembles the Avengers to fight Osborn’s team. Osborn then declares martial law in order to flush out Hill and Thor while Daken is blasted by a bolt of lightning and is severely burned. Thor declares he’s done hiding so Osborn orders Sentry to find and kill the God of Thunder, but receives a message from Taskmaster telling him to turn around and sees Cap’s shield flying toward his face. Meanwhile, the President is watching the invasion and orders the Secretary of State to mobilize all available military forces to be dispatched to Broxton in order to arrest Osborn’s forces for treason. Back at Asgard, Osborn is struck down by Cap’s shield as he and his forces descend onto the battlefield in order to aid the Asgardians while Thor is confronted by Sentry.
As the Avengers advance, the team is met by the Hood and his gang while Hill returns to Stark’s hiding place just as a briefcase arrives, while Thor and Sentry continue their fight and Cap and Norman face off. As Norman strikes Ms. Marvel down, his Iron Patriot armor is completely shut down by the arrival of Stark in his MK III armor so Osborn orders Sentry to annihilate Asgard in which he does. Cap finds Osborn in the wreckage and places him under arrest; Osborn’s armor explodes and reveals his face which is painted in the image of his alter ego. The event is witnessed across the country on live television while Osborn begins raving until Spidey punches him and Thor demands to known Loki’s whereabouts, but Osborn just points overhead to draw attention to Sentry who’s now fully possessed by the Void. With the Void fully possessing Sentry, the creature begins making short work of Cap’s team and Loki summons the Norn Stones away from the Hood to use them to empower Cap’s team. The Void realizes what Loki has done and rips him apart but before he dies, he begs Thor to avenge him so the God of Thunder goes on the offensive, pummeling the Void with all his might.
Stark tells Thor to move the Void away from Asgard and commandeers the Helicarrier to crash into the Void which reverts it back to Robert Reynolds and Thor is forced to vanquish him and send him into the sun. In the aftermath, the Hood and Madame Masque escaped the wreckage and began a race against time to reach Count Nefaria while Osborn attempts to escape during a crash of the Helicarrier, only to be stopped by Volstagg and Rogers. When he’s returned, Moonstar attempts to escape and is stopped by Stark after Barnes and Danvers fail to do so. When Bucky asks Rogers what he’s going to do next, he reveals his visit with the President who desires Steve take over in Osborn’s positions to which he agrees on the condition it’s done his way, which leads to the removal of the Superhuman Registration Act (SRA). At the same time, the New Avengers race after the Hood and Madam Masque to face the two and Count Nefaria, but the three villains are taken down just before Luke Cage receives a call from Jessica Jones over the repealed SRA. A number of heroes and Asgardians then gather at Stark Tower where one of Asgard’s remaining towers appear on the Tower in place of the Watchtower and Thor declares Earth and Asgard as allies while Rogers appears, declaring there’s work to be done.