The Great Louse Detective

Kelsey Grammer as Sideshow Bob

"The Great Louse Detective" is the sixth episode of the fourteenth season of the American animated television sitcom The Simpsons. It originally aired on the Fox network in the United States on December 15, 2002. In the episode, the Simpson family wins a free spa weekend, and Homer is nearly killed when a mysterious figure locks him in a sauna. Chief Wiggum decides to hire someone who can think like a murderer in order to find the mystery assailant. Bart's mortal enemy Sideshow Bob is sent to live with the Simpsons so he can help find Homer's attempted killer, who turns out to be the son of a man whom Homer drove to insanity. Since airing, the episode has received generally positive reviews from critics, though it has been cited for not being as good as some other Sideshow Bob episodes.

The Simpsons win a free spa weekend. At the spa, Homer is nearly killed when a mysterious person locks him into an incredibly hot steam room with a spanner. Fortunately for Homer, Krusty the Clown unlocks the door, letting an unconscious yet alive Homer out. This prompts Homer and Marge to see Chief Wiggum, who suggests that they seek help from someone who can understand a murderer's twisted mind – Sideshow Bob, who is released from prison, much to Bart's discomfort. To ensure Bart's safety, Wiggum places a shock bracelet on Sideshow Bob's ankle to keep his murderous urges at bay when he comes to live at the Simpson house. Sideshow Bob asks Homer to list all the people who may want him dead, and decides to follow Homer around to investigate who the mystery assailant could be. During their day, they end up at a repair shop, where Homer chastises the mechanic, Junior.