Having seven invisible monsters to hang out with during the summer holidays is pretty great, but now it's time to go back to school, and if Nelson's not careful, the Deadly 7 are going to get him into serious trouble. The monsters agree to stay away (and hang out in London Zoo), but there's one problem: something huge and invisible has started rampaging through the French countryside and it looks like Nelson and his monsters might be the only ones who can help. Who better to stop one enormous terrifying monster than seven little angry, sneaky, greedy, vain, adorable, thieving, farting monsters? That's right, Stan, Puff, Nosh, Miser, Hoot, Crush and Spike are here to save the day!