Hulk is walking on train tracks as a train is coming from behind. Thinking being attacked, Hulk stops the train cold with a single punch. The vehicle stumbles, a long fall awaits. When passengers fear for their lives, Hulk puts the wagons back on the tracks and leaps away.
His jump takes him to the middle of lake Michigan. After swimming to the Chicago coast, he takes a nap and turns into Bruce Banner.
Without money, Banner gets a janitor job at Soul-Star Research. Owners Stan Landers, Mark Revel and Alexandria Knox are working late that night. They are developing a device that may "collect and record electrical brain waves of any person in history". Banner overhears a design problem and provides them the answer. When questioned how a regular janitor could know about advanced electronics, he comes out clean revealing his true name. In awe since their work was inspired by some of his, they invite him to witness the final test after implementing Banner's adjustments. Obviously, they ignore Banner's alter ego is the Hulk...
The device's first cannon blast absorbs so much energy than the machine breaks apart revealing
Zzzax, a being made of pure energy! (Once called the Destroyer from the Dynamo, disintegrated months-ago by Hawkeye in
Hulk #166).
While saving Alexandria from the electric monster, Stan is grabbed and consumed by Zzzax. Banner turns into Hulk and punches Zzzax but gets punched back badly. Zzzax takes the girl and leaves.
Meanwhile, in Hulkbaster Base, Colonel Armbruster, who is suspicious of Glenn Talbot, is checking him with a scanner while he sleeps.
Back in Chicago, and a la King Kong, Zzzax climbs the 100-floor John Hancock Center skyscraper carrying Alexandria, soon followed by the Hulk while police patrols gather in the streets under a pouring rain. The two monsters fight bravely on the terrace but there is no clear winner. Suddenly, Mark Revel shoots Zzzax with a spear from a helicopter. The spear is connected to the chopper with a metallic rope. Revel flies into the storm, getting hit by a thunder that destroys the helicopter and vanishes Zzzax.
Hulk catches Revel in midair, who meets Alexandria soon after. And the Hulk? Gone, again, in loneliness.