The Simpsons Season 12 Episode 18 - Trilogy of Error Episode Title:Trilogy of Error.Episode Description: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, but finds herself at one point at West Springfield Elementary. 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.