The film revolves around a cadaver who seems to bring misfortune on those who come in contact with it.
Although there is very little corporeal manifestation of the ghosts, people seem to die when they enrage the spirit which is linked with a special cadaver - by disrespecting it or otherwise. The story takes place mostly inside a hospital, where a young female med student, Alison Blanchard, comes to learn anatomy. By observing the cadaver she was assigned, she discovers that the body had self inflicted wounds, also had a child. She soon discovers that there is something wrong with the cadaver, which they have nicknamed as Norma.
Near the end, it is revealed that the cadaver belonged to a person called Alita Covas, who once led an archaeological expedition on an Aztec sacrificial site. There she uncovered 50,000 bodies which were offered to Tlazolteotl, the Aztec god of fertility and prostitution. Afterwards, she became a prostitute, and started showing symptoms of mental imbalance. Later in her life, she committed murders and was subsequently put in a mental asylum where she died - presumably by her own hand.
Once Alison learns of the true nature of the cadaver, she decides the corpse must return to Brazil to satisfy the Aztec god. After a series of gruesome events, Alison and her classmate/love interest take Alita's now dismembered corpse and cremate her in the hospital. In the end, Alison heads to Brazil to spread the ashes in an attempt to put the spirit at rest; however, it is suggested in the final scene that the spirit remains in the hospital, as it was the place where the body was cremated.
The film was shot in a real morgue, where the cast experienced some haunting dreams. The trailer claims that real bodies were used. However, this is not the first film to use real bodies. In the 1982 film Poltergeist, in the scene where the mother falls into the pool and the skeletons attack her, the skeletons used were real, and were buried in the spot of the set. Likewise, in the 1987 Hong Kong film Men Behind the Sun, a genuine child's body was used for an autopsy scene.