Nans and Mouts set off naked and penniless from Guillaume's village, inland from Nice, with the dream of depositing treasure in the Mediterranean. To do this, the two travelers will have to travel to the sea, find a treasure, and learn to freedive to reach a haven of underwater beauty. But is it really possible to carry out such a project without money or equipment? Nans and Mouts will have to use perseverance and confidence to move towards their dream and deposit a mysterious treasure in the seabed.