In this hilarious illustrated middle grade novel in the vein of Diary of a Wimpy Kid and Matt Sprouts and the Curse of the Ten Broken Toes, a boy's time-travelling older self gives him an impossible mission: convince his class to be nice to their substitute teacher...or risk the fate of the world. Ethan seems like a normal ten-year-old, but he has a secret. It's not that he's the one who accidentally filled the sunblock container...