When a nun in a remote convent claims immaculate conception, the Vatican sends a team of priests to investigate, concerned about an ancient prophecy that a woman will give birth to twin boys: one the Messiah, the other the Antichrist.

Autumn 1944 in Tallinn, Estonia. German forces retreat as the Russian army settles in. Young soldier Aleksei is sent from the frontline to work in a prison filled with Estonian political prisoners.