Jean invites his friends and his sister over to prepare and taste a live carp. But the fish slips through their fingers and falls to the floor. They cannot find it anywhere. The only signs of its presence in the apartment are certain noises they hear. Is this a practical joke or is it Béatrice trying to get back at them after having been excluded from their last gastronomic get-together? They start to panic. What if the fish has really vanished?