The captive Captain America—forced into his Bucky costume once again—is dragged along in the assault on Hoover Dam by the bad 1950s Cap and thje Watchdogs. When word comes that they bad guys have lost communication with the train carrying the explosives, Good Cap, knowing the Falcon is safe, slugs Bad Cap, beginning a personal duel between the two Captains….
Meanwhile on the train, Falcon questions one of the henchmen and learns of the plan to blow up the dam. He forces the captive to call for pickup by copter, and then tosses the man overboard. Unwilling engineer Dave Price sets the train to derail far short of its target in Las Vegas and the Falcon grabs him and hitches a ride on the rescue copter which he easily seizes control of as the explosives detonate in the desert….
Good Cap battles Bad Cap, trying to appeal to the good man which he was before the serum drove him insane. Bucky seizes Bad Cap’s shield and knocks out the scientist arming the bomb, damaging the timer. The Falcon arrives by copter and Bad Cap puts his hand on the bomb’s detonator, intending to sacrifice himself to set it off. As his hand moves, Bucky fires with a scavenged machine gun; Bad Cap, his chest riddled with bullets, falls backward off the dam into the water below. Later, a search for his body is unsuccessful, to Bucky’s disappointment. Falcon leaves him with a word of wisdom: "that man was not like you. Remember that." The search continues in the night….