A not even remotely heroic kid must save his current timeline from a genius supervillain in this first book in a hilarious and action-packed new middle grade series from New York Times bestselling author of the Spy School series, Stuart Gibbs.

Middle schooler Johnny Day is not a good history student. He got a D-minus on his last exam. He can't even decipher roman numerals. So when Johnny visits his brilliant aunt at her groundbreaking tech company, MoleDyne, he never expects her to send him back to ancient Rome. Someone has gone back in time for nefarious reasons, and now it's up to Johnny to realign history and make sure our present doesn't get wiped out for good.

Suddenly, the kid who knows nothing about history is the only one who can save it. Armed with nothing but his wits and a snarky sentient computer, Johnny must dodge gladiators, conspirators, and catastrophes as he races to stop a cunning villain before the entire timeline collapses.

And in turn, he just might discover the hero he never knew he could be.