The Rampage of Haruhi Suzumiya

The Rampage of Haruhi Suzumiya (涼宮ハルヒの暴走) (Suzumiya Haruhi no Bōsō) is the fifth Haruhi Suzumiya Light Novel.

Book Info
What Haruhi wants, Haruhi gets!

Stunning, brash, and completely clueless about her powers, Haruhi can make anything bend to her will. Although she doesn't know it, she's a goddess who has the ability destroy the world--don't make her mad! Luckily, she has her SOS Brigade (a club comprised of her high school's most extraordinary students) to keep her happy.

This fifth volume in the wildly fun and unpredictable Haruhi Suzumiya series features three short stories for Haruhi's every mood--an endless (never-ending) summer, a heated (overheated) competition with the computer club, and a ski trip getaway (with a dangerous blizzard!).

Join the frenzy and fun with the fifth book in the phenomenal bestselling series that took the world by storm with over 4.5 million copies sold.

Summary
This novel consists of two short stories and one novelette.

Endless Eight
エ ンドレスエイ
 * You may be looking for the episodes Endless Eight I, II, III, IV, V, VI, VII, through VIII

Haruhi drags the SOS Brigade around to do various activities, including swimming in a pool, going to an O-bon festival, playing with fireworks, and bug hunting. Kyon becomes plagued by an increasing sense of déjà vu as the activities continue. One night, Mikuru calls Kyon in a panicked state. Kyon meets up with her, Yuki, and Itsuki to find that the world has been experiencing an endless loop of events from August 17 to August 31. When time reaches August 31, time resets and everyone's memories are erased (albeit not thoroughly). This is caused by the fact that Haruhi does not want summer to end because she feels she still has something she must do. Yuki reveals that this is the 15,498th time they have looped, as well as the 8769th time they have discovered the loop. As Haruhi closes up the summer activities, in a moment of déjà vu, Kyon discovers the answer, and invites the rest of the SOS Brigade over to his house to do homework. Because Kyon and Itsuki have so much homework left, while Haruhi did all hers in July, she allows them to copy her answers. Kyon afterwards finds himself on September 1, ending the loop.

The Day of Sagittarius
射手座の日
 * You may be looking for other uses of The Day of Sagittarius.''

Anxious to get their computer back from Haruhi, the Computer Research Society challenges Haruhi to a 5v5 game on the new video game developed by the Research Society: "The Day of Sagittarius III", putting four laptop computers on the line. Kyon persuades Itsuki and Yuki to play the game honestly without using any supernatural powers, however Haruhi may react. On the day of the game, Yuki discovers that the Computer Study Group has cheated: they have disabled the fog of war on their side, and have a teleport function that the Brigade does not. Kyon allows Yuki to turn the tables provided that she stay limited to Earth technology. Yuki forces the Study Group to have a limited map and changes the teleport function so that everyone is forced into a position that practically makes the SOS Brigade automatically win. Awestruck by Yuki's hacking abilities, the president of the Computer Study Group asks Yuki to come in occasionally to help, and although Haruhi objects, Kyon realizes that Yuki enjoys playing with computers, and tells her to go visit the Computer Study Group when she feels like it.

Snow Mountain Syndrome
雪山症候群

During the Christmas party mentioned in The Disappearance of Haruhi Suzumiya, Tsuruya invites the SOS Brigade to her family's villa. The SOS Brigade sets up a plan to have a fake murder mirroring that of "Remote Island Syndrome", even with the same characters. Kyon, Haruhi, Yuki, Itsuki, Mikuru, Tsuruya, Kyon's sister, and even Shamisen arrive at the villa to ski. An unexpected storm comes up, isolating the SOS Brigade members from the others. Yuki informs Kyon that there is an external factor causing the storm. The SOS Brigade take shelter in a mansion, where they find that time is skewed, other forms of reality alteration are occurring (e.g. spontaneously summoned objects), and the formerly mentioned external force is interfering with Yuki's connection to the Data Overmind, as well as giving Kyon strange visions. The mansion is sealed shut upon their entrance. Haruhi and Kyon split off from the rest of the group to search upstairs, and Haruhi takes the opportunity to confront Kyon about how he and Yuki have been acting differently around each other lately. Kyon confides in her about the threat of Yuki being forced to leave the SOS Brigade, only substituting "family issues" for the Data Overmind. Haruhi accepts his advice not to take action yet, and he in turn promises to support her in fighting the Data Overmind if it does come to Yuki leaving the brigade. The SOS Brigade take individual bedrooms in the mansion, and each member sees a duplicate of another member acting grossly out of character. Yuki catches a fever, something very strange for a humanoid interface. Itsuki finds a puzzle on a door and believes it will execute a program that will let them out. Haruhi and Itsuki solve the program with a clue from Yuki and are led out to the world they came from. Itsuki tells Haruhi that the mansion was the result of self-induced hypnosis, but Kyon is not convinced that she wholly believes this. Kyon prays for a good year.