Senku and his men manage to create a map of the most precious raw materials thanks to aerial research from a hot air balloon, but they find themselves facing the problem of food supplies, given the considerable increase in the village's inhabitants. They decide to aim for a food revolution through the production of good bread that can be preserved for a long time. In the meantime, Senku, who has gone out to sea with a small boat for experimental purposes, has a shocking encounter...