Back To Before - Megamorphs #4 (The fourth book in the Animorphs, Megamorphs series)

Jake's finally weakened. After a grisly battle, the Drode offers the Animorphs' leader an escape from the terrifying pressure. He'll reverse the decision to start the Animorphs. Now, there's no morphing, no missions, and no knowledge of the Yeerks. That is, until very strange things begin to happen and Jake, Rachel, Tobias, Cassie, Marco and Ax are forced to confront their new reality. What would you do if you had the opportunity to change your life? Not just where you live or who you hang out with, but your past, present, and future? Sounds like it might be pretty cool, right? Well, that's what Jake thought. He thought it might be easier if the Animorphs had never existed. If they'd never met Elfangor. If they all had the chance to be "normal" kids. Jake gets his wish. But things aren't quite as simple as they seem. Just because the Animorphs no longer exist doesn't mean the Yeerks no longer exist. Except now Jake, Rachel, Tobias, Cassie, and Marco can't morph. They don't even know the Yeerks are out there. And it's not such a wonderful life. . . . Jake, the leader of the Animorphs, is given the chance to reverse his decision to start the group, but once he accepts the offer, strange things begin to happen and the team is forced to confront the new reality.