In Raiano, Italy, the feast of S. Venanzio is celebrated every year. Beside the official celebrations, the most secret and oldest ceremony is the "Cult of Stones": the devotees enter the caves where the saint used to live according to tradition, and rub their bodies on the stones to heal from evil.

While stationed in Asia, six American G.I.'s witness the secret ritual of Lamians (worshipers of women who can change into serpents). When discovered by the cult, the High Lamian Priest vows that "the Cobra Goddess will avenge herself". Once back in the United States, a mysterious woman enters into their lives and accidents begin to happen. The shadow of a cobra is seen just before each death.