Farnsworth explains that he is a proud scientist who greatly admires classic geniuses of history, mainly Leonardo da Vinci, and it pains him that one of his relatives (Fry) is such an idiot.
After two weeks of fruitless research, Farnsworth orders Bender to steal Da Vinci's original Last Supper, and using an x-ray machine, learns that Saint James was a robot.
He carelessly reveals that Da Vinci's secret is in a fountain, and proceeds to self-lash himself and fakes death to deny them any other information.
He fights a mutant octopus for the coins and discovers a secret door that leads to a room filled with many of Da Vinci's famous inventions.
Fry confesses his stupidity to Leonardo, who sympathizes and says that he is actually the dumbest person on planet Vinci, and lived on Earth during the Renaissance because he could not withstand the continuous bullying from his race.
Fry helps Leonardo build the Machina Magnifica, under the assumption that they are plans for an ice cream machine.
The people of Vinci laugh at the failed machine, and Leonardo defiantly pulls a lever and is killed by a giant cog that falls on him.