Kyon arrives at the meeting point of the SOS Brigade to find a surprise--a former middle school friend called Sasaki, and she is pretty, which makes Haruhi jealous.
As Kyon and the Mikuru from the future complete the vague scavenger hunt laid out for them, their mission takes a more dangerous turn when Mikuru is kidnapped by a group of espers, time travelers, and aliens.
Kyon is surprised when Nakagawa, his middle school classmate, calls him, but when Nakagawa confesses he needs Kyon's help to tell a beautiful girl about his true feelings, Kyon realizes Nakagawa is talking about Nagato.
"A new school year means fresh blood for the SOS Brigade! But not just anyone can join this elite group of alien-, time traveler-, and esper-hunters! As Haruhi puts the new recruits through their paces in one timeline, the veteran members visit the ailing Yuki in another. Yuki reveals that her illness may be the work of other humanoid interfaces like herself, but when Kyon rushes to confront them, he runs into a familiar face he had hoped he would never see again...!"--Back cover.
Yuki and her friends are trapped on the snowy mountain by a storm and supernatural forces that have cut Yuki off from the Data Overmind. When Kyon is awakened from sleep by Asahina climbing into his bed, he realizes that it cannot be the real Asahina and, when Yuki collapses shortly afterward, they all realize they must escape this situation soon.
Kyon, who usually only wants life to be normal, is upset to discover that Haruhi Suzumia and the SOS Brigade, along with their search for supernatural beings, have completely disappeared.
Haruhi Suzumiya, an eccentric, outspoken high school girl, founds a new club, The SOS Brigade, in order to aid in her search for aliens, time travelers, and ESPers.