It is revealed in "The Duh-Vinci Code" that Da Vinci travelled to earth milleniums ago, where he was considered a genius for his many inventions. He soon returned for his home planet for being surrounded by people much less intelligent than him. Later, the other inhabitants arrive to witness Da Vinci's creation. However, Fry discovers it is a doomsday machine, which Da Vinci plots to use in destroying his enemies. Climbing into the machine, Fry shuts it down before it could kill anyone. Da Vinci tries to reactivate it by pulling a lever, only to be killed when a large cog crushes him.