In a quest for power and freedom, five young ceremonial magicians gather at an abandoned adobe cavalry fort to perform a dangerous act of necromancy. Led by the ambitious Powell Davidson, the group includes Jane, Marisa, and two others who have recently broken away from their former mentor, the renowned occultist Donald Graham. Powell, driven by his desire for Marisa and his resentment of his subordinate position, seeks to prove his superiority over Donald and claim Marisa as his own.

Unbeknownst to the others, Powell's true goal is to summon the vengeful spirit of Major Aaron Parker, a notorious murderer hanged in 1875. The ritual succeeds, but Parker's spirit proves uncontrollable. He kills two of the magicians before escaping to wreak havoc on the city, targeting the descendants of those who condemned him.

As the body count rises and the police close in, Powell, Marisa, and Jane are forced to seek Donald's help to stop Parker's killing spree. Tensions mount as the slaughter continues, and the group's complex relationships are tested to their limits.

In a final desperate attempt, they confront Parker in the haunted ruins, where their passionate and turbulent dynamics reach a violent and deadly climax. This single night of terror and death will forever change their lives, revealing the true cost of their dark ambitions.