Joseph Thorne is an intelligent, yet shady Denver police detective. One day, he comes across a series of bizarre, brutal, and ritualistic murders and is driven into obsession with the puzzle box associated with the crimes, known as the the Lament Configuration, eventually solving the puzzle. Upon solving the box, he becomes obsessed with unmasking the mysterious figure connected to the crimes, known only as "The Engineer". When discovering that "The Engineer" has kidnapped a child, he begins hunting for the figure, who in turn taunts him, killing off many of his friends, leaving one of the child's fingers at every crime scene.
Eventually, he is driven into insanity while working on the case, and is subjected to various psychological torments for much of the film, such as brutal hallucinations, and soon discovers that this is only the beginning of his punishments for the cruel life he led. The Cenobites, a race of mutilated demons, eventually appear to him, and the lead Cenobite, "Pinhead" reveals that all of the events have happened because he has been in The Labyrinth ever since solving the box. It is also revealed that "The Engineer" is a personification of his cruelty. Pinhead proceeds to wrap chains and hooks around Joseph's face and informs him that this is only the beginning, and that he will have to repeat the events for all eternity, as a consequence of the cruel life he led.