Plot
After staging his death at the hands of Clint Barton, [a] Bruce Banner realizes the Hulk always returns from death through a "green door." His vindictive "Devil" Hulk personality begins to emerge at night, or when Bruce is threatened. Investigative reporter Jackie McGee follows him, wanting to become powerful after the "Savage" Hulk destroyed her home as a child. Walt Langkowski contacts her and agrees to help her in her search, only for his Sasquatch form to become possessed by Brian Banner's spirit and rampage. Devil Hulk stops him by absorbing his gamma radiation, taking Brian into Bruce's mind in the process. On orders from General Reginald Fortean, head of the covert "Shadow Base", the Avengers attempt to capture Bruce but are bested by Devil Hulk, forcing Tony Stark to kill him. Bruce's body is taken to Shadow Base Site A and is experimented on until Devil Hulk re-forms and escapes.
He is lured to the site of the gamma bomb that created him by Brian and is attacked by Carl Creel, enhanced by Shadow Base with gamma absorption powers. Creel accidentally absorbs Brian, who possesses him and opens the green door to the "Below-Place", the bottom layer of Hell. Brian explains to Bruce that after being killed a second time in the Chaos War, [b] the "One Below All", the ruler of the Below-Place and the source of all gamma, took his form and plans to possess Bruce. Creel restores Devil Hulk's gamma, allowing him to defeat the One Below All and close the door, returning them to Earth.
Shaken, Bruce goes to Betty Ross and she is killed by Carl Burbank, working as a Shadow Base assassin. She revives as the gamma mutant Red Harpy, while Leonard Samson, back from death through the green door, interrogates Devil Hulk, who explains that he is the manifestation of Bruce's desire for a protective father figure. Rick Jones's body is stolen by Shadow Base and Devil Hulk returns to Site A, where Fortean uses UV radiation to turn him back into Bruce. Burbank wounds him, forcing his "Joe Fixit" personality to take over, who outwits and kills Burbank. Shadow Base revives and mutates Rick with Emil Blonsky's DNA, sending him after Devil Hulk, who defeats him with the help of Red Harpy.
Devil Hulk pulls Rick's withered human form out of the mutant's corpse, while Fortean steals the body and kills Langkowski, leaving him unable to revive without his gamma. Fortean fuses with the corpse as Rick awakens with gamma powers and takes Devil Hulk to Shadow Base Site B, where Devil Hulk kills a degenerating Fortean in a violent struggle before dying. Joe kills Fortean in the Below-Place, halting his resurrection, and Devil Hulk revives and takes over Site B, allowing its head scientist Charlene McGowan to aid him as he and Bruce publicly broadcast their goal to end capitalistic society for the good of the planet.
Devil Hulk begins attacking Roxxon, so CEO Dario Agger unleashes several monsters on the public, which overwhelm Devil Hulk and cause him to revert to Savage form. Xemnu, summoned by Agger, kills the last monster and brainwashes the world to remember him as the Hulk. Only Savage Hulk is unaffected by Xemnu, while his brainwashing causes Bruce to lock Savage Hulk out. Inside Bruce's mind, Savage Hulk and the Green Scar find Devil Hulk mysteriously imprisoned, while Savage Hulk destroys Xenmu's influence and takes back control. He storms Roxxon with his allies as Xemnu partially digests Agger, while the Green Scar emerges and kills Xemnu. Rick reveals himself to Agger as being controlled by Samuel Sterns, having received a distress call from a future universe where the One Below All uses the Hulk to become a cosmic destroyer, inspiring Sterns to harness the power of the Below-Place.
As Devil Hulk remains trapped, Hulk rehabilitates his image until Rick frames him for releasing a large, fatal burst of gamma energy at a public event. As Gamma Flight arrives to detain Hulk, Del Frye, a young man injected by his father with gamma that was being experimented on by Shadow Base, is taken over by Sterns, killing Samson. Sterns reveals that he has control of the Below-Place, closing the green door and preventing Samson from returning to life. As McGowan transports Rick out of the battle, Gamma Flight kills Hulk, allowing Sterns, having disguised himself as the Green Scar, to imprison him within Bruce's mind. McGowan decapitates Rick with a teleporter when he attacks her while Sterns attempts to take Bruce to the Below-Place, causing Devil Hulk to break free. Having absorbed Brian's spirit after the incident at the bomb site, Sterns uses his guise to manipulate Savage Hulk into stalling Devil Hulk long enough for Sterns to kill him. He takes Bruce to the Below-Place to make him a vessel for the One Below All, who also possesses Sterns.
Samson escapes by inhabiting Langkowski's body. Returning to Site B to retrieve his body, he finds Rick's head fused with Del after the two were released from Sterns's control, while Langkowski revives in Samson's body. With Hulk imprisoned on Gamma Flight's space base, Joe takes over to escape and falls to Earth as Hulk, where he lands in New York and fights Ben Grimm. Henry Gyrich sends the U-Foes after Hulk, who kill him with cosmic radiation, trapping him and Joe in the Below-Place. As they fight Sterns, made infinitely powerful by the One Below All, the cosmic rays allow Joe to attain a powerful Hulk form that is fueled by cosmic energy. He resurrects and easily defeats the U-Foes, forcing Gyrich to call the Avengers. Harpy and Gamma Flight arrive to fight them with Joe.
While hiding out, Joe and Harpy have sex before she reverts back to Betty, having refused to do so for Bruce. She admits she was hurt by Bruce's disgust of her Harpy form after getting her killed in the first place, only to become furious when she learns Joe left him in the Below-Place. Tired of being strung alone by Bruce and his personalities, she accuses Joe of being Bruce's most selfish desires manifested and leaves. Joe takes Jackie, given the power to see hidden gamma beings after Savage Hulk's gamma burst, to the Fantastic Four to be sent to the Below-Place. Reed Richards uses his Forever Gate to send Joe there, only for Jackie to jump in after him.
It is revealed that Bruce and Sterns's ancestors were brothers, Bruce's great-grandfather having killed his brother for sleeping with his wife. In the Below-Place, Sterns takes control of Savage Hulk to kill Joe, only for Jackie to wound Sterns with a beam of gamma from her eyes. The Hulks pull Sterns's human form out of his deformed body and demand the One Below All tell them why they exist. In response, it reveals itself as an extension of the One Above All, an omnipotent being of cosmic energy, explaining that the Hulk destroys so things can be built anew. It leaves Savage Hulk to decide what to do with Sterns. Realizing Sterns's thinking had been deformed by the gamma, Hulk decides they are the same and shows him mercy because "Hulks should forgive Hulks." Langkowski uses his gamma signature to find the Below-Place, and the Hulks and Jackie leave with Bruce and Sterns. Joe promises his services to Jackie as penance for destroying her home, and when they return to Earth, Bruce, having found equilibrium with the Hulks, slips away from his friends and leaves, wondering if his decisions have made him a good person.
