Jumpman Rule Two: Don't Even Think About It - Valentine, James

The year is fifteen billion and seventy-three and Theo - teenager, TimeJumper, legend - is the biggest celebrity on the Two Planets. Theo knows there's only one rule when you TimeJump: Don't Touch Anything. They have no idea they're about to TimeJump three thousand years into the future, become invisible, spy on Theo, and try to save the world.