Doc Green (Hulk) has detected a tumor in his brain and asks Kitty Pryde (who is in the lair of Cyclops' X-Men in Canada) to remove it using her intangible powers. The tumor was created by the Extremis in the Hulk's skull (used by Tony Stark to cure Banner of the brain damage caused by the two shots he received on the neck).
Guided by an Artifical Intelligence device of Doc Green's authorship, Pryde is able to remove the tumor. The Hulk suffers an extremely painful internal bleeding, but he quickly recovers from it. He returns to his lab, the Beehive, using his teleportation apparatus, after thanking Pryde for her valuable help. Cyclops shows up moments later, wondering what could have split the impenetrable lab door in two.
At the Beehive, Doc Green tells the two assistants he's left with, Jessup Randall and Damon Veteri, not to be disturbed at his room. Doc Green falls to sleep and turns into Bruce Banner.
When Banner wakes up, he tries leaving the room. But the Artificial Intelligence device won't let him. Commanding Banner to turn back into Doc Green, the A.I. threatens to punish disobedience by killing Betty Ross (who can no longer transform into the Red She-Hulk) with a bomb hidden at her place.
Banner realizes the A.I. isn't joking and starts pounding the floor until tension turns him into Doc Green, who falls into a deep sleep.
Doc Green dreams for the first time. In his dream, New York city is destroyed and in flames. Hulk is fighting superheroes like Thor, Iron Man, the Thing, Mr. Fantastic, and Captain America. He kills them all.
Before waking up, Hulk seemingly kills Rick Jones too, and reveals his true appearance: He's got gray hair and a beard. He's the Maestro.
Doc Green analyzes his dream, calls it a "fascinating experience", feels "rejuvenated", and considers growing a beard...