According to an ancient prophecy, a woman will give birth to identical twin boys: one will be the Messiah, the other the Anti-Christ. When a Russian nun, Sister Yulia, claims to have immaculately conceived twins, the Vatican sends a team of priests to investigate. The priests are joined by affiliates of a secret society, the Vox Dei. They confirm her claim as authentic, and Vox Dei's orders are to abort both children. However, an American Jesuit, Father Fox, discovers their plan and helps her escape to Estonia.