Overview
"Treehouse of Horror 13" is the first episode of the fourteenth season of the American animated television series The Simpsons, and the thirteenth Treehouse of Horror episode. It first aired on the Fox network in the United States on November 3, 2002, three days after Halloween. It is the second Halloween episode to have a zombie related segment, and the last Halloween to have three separate writers credited for writing three stories (starting with "Treehouse of Horror XIV", only one writer is credited for writing the three stories). It is also the first Halloween episode to be titled Treehouse of Horror in the opening credits, as all prior Halloween episodes were referred to as The Simpsons Halloween Special. It is the first of these episodes not to have a Roman numeral used in its opening title.
In the episode, Homer buys a magic hammock that can create duplicates of anyone who lies in it in "Send in the Clones"; Lisa's call to end gun violence resurrects undead outlaws in "The Fright to Creep and Scare Harms"; and Dr. Hibbert invites everyone in Springfield to his island resort where everyone is turned into half-man, half-animal hybrids in "The Island of Dr. Hibbert".
Plot
The Simpson family and Ned Flanders hold a séance in the hope of communicating with the spirit of Maude Flanders. Bart tries to trick Ned by dressing up as Maude's ghost, but the real ghost of Maude, now a demonic spirit, appears instead. She asks if they're ready for tales that will shatter spines and boil blood, to which Lisa replies as "well, duh." She then pulls out a book that reads the episode's title.
Send in the Clones
In this spoof of Multiplicity, Homer's hammock collapses while he is taking a nap. He purchases a new one from a passing vendor, who warns him that it carries a curse. Disregarding this, Homer lies down and discovers that the new hammock can produce clones of anyone who rests on it. He inspects the first clone and notices that it does not have a belly button.
From Wikipedia (CC BY-SA 4.0).