The gang is at the Coolsville robot convention where the main attraction is 'Doc' Tinkerwell's battling Monsterbots. But when one of the Monsterbots wigs out and starts attacking the crowd, chaos ensues! If word gets out that his Monsterbots aren't safe, Doc will be ruined! Luckily Mystery, Inc, is on the case-and they're going to put a stop to that Rotten Robot!