Remote Island Syndrome Part 2

Key Events

 * The SOS Brigade investigates the case.
 * Yutaka is a suspect of the murder when Haruhi and Kyon get stuck outside in a cave where Haruhi thought of a possible conclusion about the murder.
 * It turns out they were all part of Itsuki's organization and was simply a prank to keep Haruhi occupied.

Summary
Haruhi and the SOS Brigade attempt to find clues to the villa owner's murder. Yutaka, the owner's younger brother, is initially suspect due to having been seen leaving the island the previous day before the storm hit. Haruhi and Kyon head outside during the storm, but find nothing. While drying off inside a cave, Haruhi comes to a startling conclusion about the murder. They return to the villa and set to devising a plan to solve the mystery. In the end, there never was a murder, for all was just a set-up.

Characters

 * Haruhi Suzumiya
 * Kyon
 * Mikuru Asahina
 * Yuki Nagato
 * Itsuki Koizumi
 * Kyon's Sister
 * Keiichi Tamaru
 * Yutaka Tamaru
 * Arakawa
 * Sonou Mori

Differences from light novel
"Remote Island Syndrome" is one of the few Haruhi Suzumiya story arcs in which the TV series significantly departs from the light novels. The premise of the story and the facts of the murder mystery remain unchanged, but how the mystery unravels is dramatically reworked to give Haruhi and Kyon more active roles. In the original novelette (published in The Boredom of Haruhi Suzumiya), most of the deductions are made by Koizumi, even though he set up the whole scenario in order to give Haruhi an opportunity to play detective. Koizumi also provides the key evidence of Keiichi's body temperature.

In the TV episode, it is Haruhi who touches Keiichi and realizes his body was warm at the time of discovery. After confirming the cruiser is gone, she spots a shadowy figure. While pursuing the figure, she and Kyon fall onto a cliff ledge and take shelter in a cave, where their combined deductions lead them to the first and second false solutions. (In the novelette, they confirm the cruiser is gone and return without incident.) After returning to the house, the two of them figure out the true solution and set up a scene to catch out Keiichi.

The scenes in which Mikuru spots Keiichi and Yutaka arguing and Kyon and his sister find the remains of Keiichi's meal were also added. In the novelette, no motive for Yutaka committing murder is provided, and though it is mentioned that Keiichi ate with a fork and knife, it never develops into a piece of evidence.

Trivia

 * This episode was broadcast as episode 8 of Season 1, and episode 11 of Season 2.
 * When Haruhi explains how she and Kyon solved the mystery, her and Koizumi's actions are based on the actions of the main characters from the Ace Attorney games. Namely, Haruhi is mimicking Phoenix Wright, Itsuki is mimicking Miles Edgeworth, and Mikuru is mimicking Maya Fey.
 * The references to the Ace Attorney series in this episode ultimately inspired three Haruhi fangames in the Ace Attorney style, know as The Turnabout of Haruhi Suzumiya.
 * At the end of the episode, Keiichi waves the knife, but it is still stuck in the notebook. This is only possible if he took the knife out of the notebook, removed the notebook, and stuck the knife back in.
 * There is an error in the animation of Haruhi's legs, which was fixed for the Blu-ray release.
 * Paranormal phenomena observed: the mysterious shadow is probably created by Haruhi
 * The mysterious shadow is a reference to "The Criminal" in the Detective Conan manga and anime series.
 * During Haruhi and Itsuki's theories of how Keiichi was murdered, live actors are used.