Maxime and Paulo are two young men in their very early twenties. Maxime is spending his summer holidays with his parents in a camping resort, which he hates, and Paulo is working in the nearest cafeteria. They hope to win a cruise to Bora-Bora by collecting capsules from pop-soda bottles. They are missing only one capsule, which is unfortunately found by Penelope, who works in the local supermarket. Unfortunately, because Penelope is not very attractive. The two boys make Penelope believe that Paulo is going to go on the cruise with her, but Maxime decides to ride along with them, in Penelope's old car, to Marseille, where the ship is leaving from. Actually the two boys plan to steal Penelope's capsule, get rid of her, and go on the cruise together. But, on their way to Marseille, they are going to meet a couple of very strange elderly people, Hermine and Gaspard.

Maxime et Paulo viennent de gagner une croisière dans les îles du Pacifique. L'embarquement est à Marseille. Il s'y rendent à bord d'une vieille 4L, et en plus, ils doivent subir la naïve Pénélope pendant le trajet. Les deux amis ont bien l'intention de s'en débarrasser. En chemin, ils rencontrent un couple de septuagénaires en cavale. Ces adultes peu raisonnables donnent une véritable leçon de vie à ces trois adolescents.