The kids discover their beloved Mr. Terupt is moving away at the end of the school year and begin hatching plans to make this year unforgettable.

"Mason and Ty were once the very best of friends, like two nerdy sides of the same coin . . . until seventh grade, when Ava Petrakis came along. Now Mason can trace everything bad in his life to that terrible fight they had over the new girl. The one thing he'd give anything for is a do-over. But that can't happen in real life--can it? As a science kid, Mason knows do-overs are impossible, so he can't believe it when he wakes up from a freak accident...