Marsupilami discovers a family of humans has just moved into the old abandoned dispensary on the banks of the Soupopoaro. They become the best of friends.
Jean-Pierre has just finished working on an important computer program. The only copy of it is burned on a CD that he has to take to Chiquito to present it to clients. Jean-Pierre doesn't notice Bibu take the CD and go play with it. Theo realizes the problem and tries to get it back. But Bibu hasn't got it any more. Will Marsupilami and Theo manage to get it back in time?
Theo and Marsupilami discover the trail of an amazing treasure, belonging to the Santa-Piaco, a Spanish galleon sunk in the waters of the Soupopoaro during the Conquistador times. Our friends learn from the wizard, Yamatunga, that the treasure has a curse on it, and anybody coveting the treasure will be struck by misfortune.
Marsupilami, Theo, Alex and Jenni set out to take part in the Chiquito roller blade competition. Theo wants to beat Tony Boss, the big show-off who won last year. Jean-Pierre gets carried away by his passion for the event and offers to coach the team.
The jungle is ravaged by a terrifying storm and there are floods. Trapped in the jungle far from home and help, Theo and his family are forced to live in the trees in the kingdom of the Marsupilamis until the water level drops. The solution more than makes amends for the problem. However, by chance, this is the day that Backalive has chosen to launch a new offensive against the Marsupilami.
Amanda, who is away studying the apes, disappears without trace. Jean-Pierre, at his wit's end, decides to set out and look for his wife, accompanied by the Marsupilami. The two buddy-antagonists confront the dangers of the jungle together. When Jean-Pierre finally finds Amanda, he has a big surprise in store. There are other Marsupilamis living in the jungle.