Teen Tony Stark, ten years away from his right era, enrolls at Columbia University to start his academic year over from scratch. As he wanders the campus he encounters a nerdy student named Chip Walters who is knocked down by a runaway Frisbee. Recognizing Chip as another science major, he asks his advice on classes and Chip highly recommends Dr Alden's class before running off to escape the obnoxious jocks. At registration Tony meets Kris DeGann and learns that Chip was lying to him to cut out competition for the good classes; Dr Alden is the most hated teacher at the school. Lining up for her class, Tony recognizes her as his ex-girlfriend Meredith McCall. He tries to duck before she can recognize him and then the lights go out, thanks to the power loss caused by the Zodiac dome covering Manhattan (seen in CAPTAIN AMERICA #449, part one of this crossover). Tony dons his gauntlets to provide light and to open the doors but realizes his chest plate, keeping him alive, is being drained of energy. He follows energy traces down to the basement where he finds a well-stocked lab....
At Avengers Mansion, Jarvis is able to communicate with Giant-Man Hank Pym and a few other Avengers who are trapped right outside the dome. The butler fills Hank in on the situation before the com-links go down....
At the school lab, Tony is able to jury-rig a force field to protect his chest plate from the energy drain, but he still needs to recharge soon. Tracing the power emissions, Tony encounters Captain America and Thor in combat with hordes of Zodiac goons and holding their own. Cap is trying to reach the skimmer to close the portal letting the thugs in and also to pierce the dome around Manhattan. Tony jumps into the fray, surprising Cap. The trio of Avengers make it onto the skimmer and take off, crashing through to the surface. They find a city in chaos with fires, looting, and sheer mayhem. Tony is able to fix the Zodiac transporter to power his Avengers Communicard in order to alert all Avengers outside the dome to meet them at the Brooklyn Bridge. At the Bridge they find tens of thousands of citizens desperately trying to claw their way through the barrier. Wasp, Quicksilver, and Deathcry are outside with Hank, waiting to be let in. Problem: they can open the barrier for only thirty seconds: do they let as many people escape as they can? Or do they admit the four Avengers, hoping to solve the problem? And either way, it will drain all power from Tony's chest plate, killing him....