1x21 - The Melancholy of Haruhi-chan Suzumiya

Haruhi, Mikuru, Yuki and Tsuruya attend a mall exhibition whilst Kyon and Koizumi attempt a puzzle. Tsuruya fights against one of the show's monsters, who is really Mori, but is inevitably defeated. In the wake of the clash, Kyon and Koizumi's puzzle is ruined, leaving them frozen in place.