While attempting to take back the Centurion Project, which appeared to be a small metallic bracelet, from Drakken, Kim managed to get it stuck around her wrist, not knowing what it does.
Later that same day, Monique told her that Josh Mankey would be at her Halloween party, and Kim felt compelled to lie to Ron and her mother so she could sneak off to Monique's party. She told her mother she was going Trick or Treating with Ron, which they did traditionally since kids, but tells Ron she had to be with her mother at a hospital-organized haunted house. Wade helped her realize that every time she lied the Centurion Project grew on her body, covering more and more of it.
Drakken and Killigan were both separately listening in to the conversation at different points of time, and they each heard one of the two lies Kim told her entourage. Thinking she told the truth, Drakken went to the hospital while Killigan headed for the neighborhood, each trying to get their hands on the Project.
At Monique's party, Kim spoke with Josh, who was dressed as a pirate. He was very intrigued by the fact that she was dressed as a princess and had a cybernetic hand, which, unknown to him, was actually the Centurion Project. As Kim continued to lie, still trying to impress him, it grew more and more, eventually covering her whole body.
Using this technology, she flew over to the hospital where the two villains were questioning her parents on her whereabouts with Ron as hostage. They fought, and she won.
Once coming clean about her lies with her parents and Ron, who already knew the truth from the villains, the cybernetic armor receded back to its original dormant bracelted form.
Ron then proposed to Mankey they go Trick or Treating, which he accepted. Josh was even agreeable with Ron's two-person unicorn costume, of which Ron was the back-end.
Kim, who had been expressing Trick or Treating as lame, regretted her decisions as her crush left with Ron, while she was grounded.
- This is one of the few episodes in the series where Kim is actually grounded at the end of the episode.
- When Dr. Drakken and Shego are eavesdropping in Kim and Wade's conversation, Drakken could hear everything. When Kim mentions to Wade that she is going to Monique's, Dr. Drakken's reaction is not shown nor does he visit Monique's place at all during the episode.
The episode was made available on the Kim Possible: The Complete First Season DVD set, released as a Disney Movie Club exclusive in 2010.
|Christy Carlson Romano||Kim Possible|
|Will Friedle||Ron Stoppable|
|Gary Cole||Dr. James Timothy Possible|
|John DiMaggio||Dr. Drakken|
|Shaun Fleming|| Jim Possible|
|Brian George||Duff Killigan|
|Jean Smart||Dr. Ann Possible|
|A.J. Trauth||Josh Mankey|
- Kim Possible Wiki: October 31st
- Disney Wiki: October 31st
- "October 31st (Kim Possible)" at the Internet Movie Database