Li ShiQing wakes up on the bus from the dream. She desperately tries to get off and manages to succeed. The bus explodes. She is struck and falls unconscious. At the hospital, ShiQing realizes she's been experiencing the event repeatedly.
Xiao HeYun wakes up on the bus, entering the Loop. He experiences the explosion twice before realizing that it wasn't a dream. ShiQing and HeYun get off and inform the police about the coming explosion. The police begin to track them.
Xiao He Yun and Li Shi Qing create a detailed timeline of the events to find clues about the explosion. They can't agree on what to say to the police. They are found and taken into questioning. They both tell the police about the loop.
ShiQing wakes up on the bus again after falling asleep. HeYun says there is a bomb on the bus, and when they announce it to the passengers, which causes the bus to explode. They determine that the bomber is riding the bus with them.
The police confirmed residues of a bomb on the bus and decided to investigate further. The masked man takes He Yun and Li Shi Qing to his secret apartment. The police question Lu Di and the other two arrive at the station.
Li Shi Qing and Xiao He Yun go in to talk to the police and lie about why they stopped Lu Di from getting on the bus. They tell the police about suspicious people on the bus. They start investigating Ma Guo Qiang.
HeYun and ShiQing decide to investigate the two remaining passengers. The bomb explodes various times. In one of the loops, a passenger ends up dead. They leave the bus shocked, and it explodes behind them.
The police investigate the explosion with Xiao He Yun and Li Shi Qing as the prime suspects. Li Shi Qing refuses to leave a traumatized He Yun, and they attempt to evade the police together.
They return to the bus and try to save everyone, but the bomb explodes. Once again, back in the loop, He Yun and Shi Qing manage to get assistance from two other passengers but realize that the bomber has an accomplice.
Xiao He Yun and Li Shi Qing get off the bus before it explodes to investigate the accomplice. They go to the police to give them clues and hopefully get more clues. However, the police are suspicious of their intentions.
The police find out the motive for the explosion, and the result is fast. They keep wondering about the source of information. Li Shi Qing asks the police officer how to stop a bomb on the bus.