When Gaston discovers Anatole building a little car as a birthday gift for Paul and Paulette, Anatole makes him promise to keep it a secret. Gaston just can't keep his mouth shut, however - he tells Pamplemousse, and they both drop by to take a look at the car. Again, Anatole makes them promise not to touch a thing, but as soon as he leaves, the two accidentally set off on a wild ride ... without the steering wheel! By the time Anatole finds them they have crashed the car in downtown Paris. The three mice must replace the engine (find a new elastic band), and drive the car back in time for the birthday party, dodging Charlemagne, human children, and a ferocious dog! Gaston and Pamplemousse learn the hard way that it is very important to keep your word.