Herbert the duck, the exiled heir of Vaucanson, returns to his homeland. He actually wants to avoid a meeting with his parents, but that's easier said than done. To move around unnoticed, he uses a potion that transforms him into a mask of death. Unfortunately, the potion causes highly unpredictable side effects, as every time Herbert laughs, he turns back into a duck. One mishap follows another, and Herbert's old home is threatened to become a place of devastation.