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. Just the slightest change to events could have catastrophic consequences. But Theo's been spending a lot of time with Quincy Carter One, the man in charge of TimeMaster Corporation. Quincy's starting to think that Rule 1 doesn't apply to him. Why not fiddle about with history? Meanwhile, back in the present Jules and Gen are too busy worrying about their first date to wonder what Theo's up to. 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. (Hopefully without Gen's Mum noticing they're up to anything). Can Rule 1 be broken? And if it can't, then why do we need Rule 2?