The police receive a phone call, warning them of a bomb on Bus No. 45 that was about to cross the bridge. However, the bomb explodes before they could send help. Li Shi Qing, the one who had informed the police, wakes up in the bus from the dream. She desperately accuses her seat mate, Xiao He Yun, of being a pervert and successfully manages to get off the bus with him. They part on unfriendly terms and the boy soon gets into a taxi that stops behind the bus. The bus once again explodes, severely injuring everyone on sight. A shocked Li Shi Qing is struck by a bike and she falls unconscious. Waking up in the hospital, she is questioned by Chief Zhang and his colleagues, who had captured footage of her and He Yun getting off the bus. While explaining the events, Shi Qing realizes that she had been experiencing the event over and over again. Chief Zhang, although sceptical, calls this a "bus loop". Xiao He Yun succumbs to his injuries. He wakes up in Bus No. 45.