Robert Simonet (Jean-Marc Thibault), a hard-working but good-hearted little garage owner, has spent a hard night on fixing in due time a car which he then has to tow away from the road in the early hours of this Saturday, completely wrecked in a crash by its careless speed-crazy driver. Upset by this event and by the coming cycle race where he is a favorite, he miss the German patrons who are back to take their car. They leave the town, but the direction of their Mercedes is not thoroughly repaired. And now, Robert is torn apart : shall he go to the police to have them calling back the German tourists, to the cost of the cycling race and of his reputation as a skilled mechanic? He does... but the police keeps him in custody, and the Germans seem to be now unreachable...