 However, on the morning of December 18, Kyon arrives at school and finds that the very nature of his reality has changed; Haruhi and Itsuki Koizumi are missing, Ryoko Asakura has mysteriously returned, Mikuru Asahina does not recognize him and Yuki Nagato is an ordinary human.Only Kyon is aware that everything is different, and no one else remembers anything about Haruhi or the SOS Brigade.The only clue Kyon manages to find is a bookmark left by the alien version of Yuki before everything was changed, telling him to gather "keys" to run a program.