About the Book: Have you got what it takes to keep Dennis and Walter from erasing each other from history? It’s a week night and you have a sleepover round Dennis’s house! It’s going to be EPIC! … Is what you thought before Dennis pulled a prank that shut the school down and you were forced to go to work with his parents. BORING! … Is what you thought before you, Dennis, Gnasher and Walter got sucked into a time machine that sent you back in time to when their parents were your age! AWESOME! … Is what you thought before Dennis and Walter messed with the timeline and started disappearing.