The story follows a light-bulb-head orphan, named Otto Osworth, who is under the watchful eye of the nasty nun of the School for Wayward Tots, named Sister Thornly, who treats him badly for reading history books. Otto soon finds his ticket out of the orphanage, by using his knowledge of history to talk time cop Buck Tuddrussel and his robot Larry into abducting him. He is suddenly zapped to the satellite and to Eli Whitney's time where they must convince him to invent the cotton gin, not the flesh-eating robot.

Tuddrussel is showing Otto some outrageous souvenirs from the past when they get a mission to the time of the Trojan War, where the Greeks sneaked a giant, wooden horse into Troy's kingdom, filling it with solders to attack when the horse is opened, to win the war. Instead, they're filling it with candy for the king of Troy's birthday!