“Trilogy of Error” is the eighteenth episode of Season 12. It aired on April 29, 2001. The episode was written by Matt Selman and directed by Mike B. Anderson. Frankie Muniz and Joe Mantegna guest star.
Homer’s thumb is cut off following breakfast and the episode follows three different paths. Homer’s day: as he and Marge race to get his thumb reattached. Lisa’s day: as she misses the bus and tries to get to school so that she can win the science fair. Bart’s day: as he and Milhouse make use of a stash of fireworks that Fat Tony has illegally smuggled into the country. In the end their respective paths come together.