Boireau sets off for a scientific mission on behalf of the Society of Scholars of Saint-Valéru-en-Guingois, of which he is president. They are exploring the bottom of the ocean for the famous sponge used to make towels. After having raised the national flag, Boireau leaves the dock for the open sea.

Our explorer rows day and night, until he is the victim of a catastrophe: his ship, hit by an iceberg, falls to the bottom of the sea. Boireau saves himself on a raft and rows in convoy with his trunk. At the end of the ninth day he reaches an island where, worried about his mission, he puts on the diving suit and descends into the depths of the sea.

Unfortunately some natives see him coming out of the water and the king of the Mabouloufoques mistakes him for the Messiah his people have been waiting for and rescues him from the spit and takes him on a flags dressing in place of the previous God. However Boireau is tired of being adored by men and one night escapes to regain the sacred soil of his homeland, where the members of the Society of Scholars cry bitterly for their president that they believe a victim of his sense of duty. Boireau is properly cheered and becomes the legendary hero of the Saint-Valéry-en- Guingois.

Bulletin Pathé