Captain America was kidnapped by Arnim Zola and brought to Dimension Z, where Zola ruled as a harsh dictator. Zola wanted to use the Super-Soldier Serum in Cap's genetic code to make his own race of super-beings, but Cap broke free before he could finish his experiments, taking Zola's infant child Ian with him. After spending 12 years in Dimension Z raising Ian as his own, Cap defeated Zola and escaped with Jet Black, Zola's daughter, but believed both Ian and his lover Sharon Carter lost.

Upon his return the villainous Iron Nail neutralized the Super-Soldier Serum within Cap, causing him to rapidly age into an old man. Meanwhile, Zola began his invasion of Earth from Dimension Z. Ian snuck through as well, reunited with his father, then led the Avengers against Zola. Falcon and Jet Black freed a captive Sharon Carer from Zola's fortress. When it was discovered Zola's mutate soldiers were a distraction from his true attack, a powerful bomb, Falcon flew the bomb into the atmosphere just as it detonated!

---