A battle with Ultron leaves The Avengers defeated, with the heroes killed during the fight, and the world at the mercy of Ultron’s machine army. Iron Man is told by Captain America to take the Avengers’ children to a fortified refuge hidden above the Arctic Circle. The children’s are James Rogers (son of Black Widow and Captain America), Henry Pym Jr. (son of Giant-Man and Wasp), Azari T’Challa (son of Black Panther and Storm), and Torunn (daughter of the absent Thor and Sif). Stark secretly raises and trains the children for 12 years. One day, The Vision arrives at the refuge after hiding for over a decade from Ultron. He has come to inform Stark that “The Boy” is alive. While the curious children are eavesdropping on Stark and The Vision, James accidentally activates a series of Iron Man-style robots, called the Iron Avengers, that mimic the looks and abilities of Captain America, Hawkeye, Black Panther, Thor, Black Widow and Giant Man. Because they are programmed to defeat Ultron upon activation, they take off to do so, whereupon they are detected by Ultron’s worldwide sensors, revealing the location of the refuge. Easily defeated by him, Ultron then reprograms the Iron Avenger robots to follow his commands, proceeds to the refuge and invades it. Stark, now dressed as Iron Man, is able to stall Ultron long enough for the children to escape, but he is eventually subdued and captured. Sneaking into Ultra City to rescue Stark, the four young Avengers run into Francis Barton (son of Hawkeye and Mockingbird), the new Hawkeye. They decide to team up with him and his group of resistance fighters, called the Scavengers, to rescue their guardian. The five manage to escape with Stark from Ultron’s trap in his citadel, and they head to the desert, along with an older Betty Ross, where Bruce Banner, in an effort to submerge The Hulk, has decided to hide out and keep away from other people for their own safety. After he refuses to help them, James comes up a plan to lure Ultron there so he can cause The Hulk to appear, destroying the robot. The young Avengers fight the mechanical doubles of their parents, and manage to awaken The Hulk, who defeats the Iron Avengers. However, Ultron attacks The Hulk and defeats him before attacking the young Avengers, nearly killing them. Pym revives The Hulk, who then ultimately destroys Ultron, ripping him in two. Then, in a fit of rage, The Hulk begins to turn on the young Avengers, but is subdued by Betty. Finally, to stop Ultron from rebuilding himself, Toruun takes the two halves into space and throws them away in opposite directions. She nearly suffocates and freezes in the process, resulting in her father, Thor, rescuing her and explaining why he left her on Earth. Thor invites Torunn to join him in Asgard, but Torunn chooses instead to return to her family on Earth. As a parting gift, Thor sends her back to Earth in full Asgardian armor. With Ultron finally defeated, the five young Avengers prepare to return to Ultra City, to deal with Ultron’s remaining forces and rescue the populace.