During the Renaissance, Léonard is an inventor convinced that he is the greatest genius of his time. In his workshop, he constantly imagines new machines, inventions, and experiments, often far ahead of their era. To test them, he regularly relies on Basile, his lazy and unlucky apprentice, who inevitably becomes the first victim of his creations. Between anachronisms, scientific disasters, and absurd rivalries, the series humorously plays with the figure of Leonardo da Vinci and turns each new idea from the self-proclaimed “genius” into an experiment that rarely goes according to plan.