A man becomes involved in a memory manipulation operation to try and regain lost memories. He thinks the exercise may help repair his failed marriage, but accidentally ends up with the mind of a serial killer.
Zha, a top student with a high IQ, goes on a journey with Mo, a professional debt collector and sometimes hooligan, in order to face down her own neurosis, as well as cure Mo of his extreme insomnia.
The story starts because of one journey. Seven people who have never met before climb aboard the same ride that goes into a seemingly endless tunnel. Despite the countless trials, corpses that mysteriously appear, past acquaintances that returned from the dead and an unseen danger threatening to swallow them whole, it's as if they are trapped in an enclosed space where there is no escape.