Seeking to duplicate the success of his first android, the Human Torch, Phineas T. Horton created a new synthetic android, Adam-II. However, Adam-II proved to have goals for world conquest, and took Horton prisoner, replacing him with an android duplicate while he began to construct an army of androids. During his time as Adam-II's prisoner, Horton learned that Adam-II planned to replace an American politician with an android.
In 1946, when the Human Torch and Toro came to visit Horton, they were confronted by the imposter, and when the Torch recognized it as a fake they melted it down. Adam-II then revealed himself to them, declaring his goal of conquering the Earth and repopulating the globe with an android population. Adam-II offered the Torch a place with him, but the Torch refused, and fought Adam-II's androids with Toro. When they tried to melt through a wall they thought Adam-II was hiding behind, it turned out to be a vat of water, and their flames were snuffed out.
Adam-II placed the Torch, Toro and Horton inside of a water tank and began to fill it with water to eliminate them all, but they were saved by the Patriot and alerted their allies in the All-Winners Squad. Adam-II brought an android duplicate of Jack Kennedy to the site of a rally in Boston for the real Kennedy, but Captain America and Bucky found Adam-II and the imposter first, and fought back against his androids. Captain America fled to the Old North Church to signal his teammates, but one of the androids caught up to him as he was sending his flare. The android crushed his ribs from behind, but the Captain managed to destroy it with his flare gun, then light a flare for his allies before dying.
The rest of the All-Winners Squad caught up to Adam-II, and he used his androids to hold them back while he attempted to abduct Kennedy, but Captain America suddenly appeared to defend Kennedy. As he had received an electronic signal from his android at the church, Adam-II was shocked to see the Captain alive, not realizing it was the Patriot now wearing the uniform. Adam-II attempted to run the Captain down with Kennedy's car, but the car skidded on a pool of oil from Adam-II's smashed lackeys, and he veered out-of-control, smashed into a building, and perished in the resulting explosion.