Après la vente d'un bistrot, une jeune femme oublie dans un taxi l'argent de la transaction, ruinant ainsi son couple. Afin d'échapper aux reproches de son époux, elle simule l'amnésie.

Albert is the irremovable waiter in a small bistro that has just been sold by his former bosses, Angèle and Léon. Angèle, having forgotten the ten million paid by the notary in a cab, prefers to feign madness rather than incur her husband's wrath; but Léon, in turn, eventually learns what has happened to his money, goes mad and kicks out the honest cab driver who comes to return the lost sum. A phone call from the police station later informs Albert that the money is at his boss's disposal; but as the boss is now in an institution, Albert borrows his identity papers and goes to collect the money - which he pays in full to the pari-mutuel betting house. After a series of shocks and counter-shocks, Angèle and Léon regain their senses enough to watch for the outcome of the race, and share with Albert the final winnings, which are very substantial.