Clint vanishes from the battle and wakes up a few blocks away from the action, and now he's sixteen. He doesn't know how the hell he ended up in NYC, but he knows he has to lay low. Clint's pretty good at laying low, even as a kid, and it takes a little while for Phil and the rest of the team to figure out what happened to him, and a while longer to actually find him. They also have to convince him that they can be trusted. It's magic, of course, but the kicker is that the spell comes with a terrible choice attached, and Clint is not in the best shape to be making choices about his own life.