Bucky finds out he has seven-year-old twins, which is news to him. After rescuing them from the GRC's Commission on Superhuman Activities branch, he realizes that they might also be a little super soldier-y. Not a lot, not exactly like him, at least for now. But even a little is enough to make some people interested in how that happened and how that could be replicated to create a whole homegrown super soldier squad. Bucky and eventually Sam (it's not like he was going to sit this one out once he heard what was going on) wind up on another worldwide trip to keep the twins out of the CSA's hands and to figure out where they came from. Also, Bucky figures out how to be a dad. Therefore: tea parties, Disney marathons, and freeze tag, as well as running from shady government entities, underground crime lords, and the newly minted U.S. Agent.