In post-World War II Asia, a group of American GIs led by Tom Markel infiltrate a sacred cult ceremony dedicated to the worship of Lamians, mythical snake people. They are discovered and narrowly escape after witnessing a terrifying transformation ritual involving a cobra. Back in the United States, the men resume their lives, but the memory of the cult and its exotic high priestess lingers. Soon after their return, strange deaths begin to befall the group, each incident shrouded in mystery and terror. They encounter Lisa Moya, a mysterious and alluring woman who seems to have connections with the secretive cult they encountered overseas.

As their numbers dwindle and paranoia escalates, the surviving friends suspect they've been targeted by the cult for violating its sanctity. Their desperation grows as they struggle to uncover the truth behind Lisa's intentions and whether she is connected to the menacing events that unfold around them. Desperation turns to terror as they realize that their enemy is not just human but possesses otherworldly powers. The film builds tension as the lines between reality and superstition blur, leading to an inevitable clash between the soldiers' rational world and the arcane vengeance of the Lamians.