In a dark, decrepit house, a group of eight people wakes up to find themselves trapped, with no memory of how they got there. They soon discover they are part of a twisted game orchestrated by a notorious serial killer known for testing his victims' will to live through diabolical traps. Each person is connected by a common past they must figure out if they are to survive. The house is filled with a deadly nerve gas that will kill them in two hours unless they find the antidotes hidden in various parts of the building. As panic sets in, the group is forced to work together, deciphering clues and facing harrowing challenges that test their limits and reveal their darkest secrets.

Meanwhile, a police detective becomes embroiled in a tense race against time when he discovers his own son is among the trapped individuals. Negotiating with the killer, who is now in custody, the detective tries to unravel the location of the house and the reason behind his son's involvement. The killer, however, has his own twisted agenda, drawing the detective into a psychological game of cat and mouse. As the detective delves deeper into the killer's labyrinthine world, he must confront his own moral compass and the lengths he is willing to go to save his son, leading to a series of choices that blur the lines between right and wrong.