As a measure to keep his labs from falling into the wrong hands should the Fantastic Four become incapacitated, Mr. Fantastic programmed the top floors of the Baxter Building to shift into the Negative Zone, sealed within an impenetrable force field. With the FF apparently dead after the battle against Onslaught, the labs have shunted into the alternate universe where Annihilus tries to breach the force field. Using his Cosmic Control Rod, he finally succeeds, only to encounter another security measure: the N-Zone portal causes the Rod to feedback, absorbing Annihilus and sending him hurtling through the Multiverse.
In the Microverse, while Commander Rann, Marionette and Bug fight Baron Karza's Dog Soldiers, Annihilus briefly appears, but Bug is pulled along in his wake. Surmising that this alien being has less-than-noble intentions, Bug becomes determined to wrest the Control Rod from Annihilus' grasp, as they shift through time and space.
They tumble through scene after scene of various points in the history of the Marvel Universe (and other universes), sometimes as unwitting participants, sometimes as mere bystanders. The two are there when the irradiated spider bites Peter Parker, when Bruce Banner is bombarded by gamma radiation, when young Matt Murdock is struck by the isotope canister, when the bat crashes through Bruce Wayne's window, when Frank Castle's family is gunned down, when Thor is briefly transformed into a frog, when Victor Von Doom finds his college mate Reed Richards reading his notes, when Tony Stark decides to quit drinking, when adamantium is injected into Logan's body, when Stephen Strange has his fateful car crash, when the Beast's experiment backfires, making him furry, during a battle between Captain America and the Red Skull, during a rare lapse in Black Bolt's silence, and during a Calvin and Hobbes toboggan ride.
The Control Rod exchanges hands several times during the adventure, then finally Bug grasps it and they end up in the Negative Zone. As Bug uses the Rod to return to the Microverse at the same point he disappeared, Annihilus is doomed to endlessly repeat the process of breaking into the FF labs, only to be shifted back outside them. At least, till he gives up.
This issue also includes satirical puzzles and games by Fred Hembeck.