After her mother's death, Masha and her father, a priest, move to Lake Brosno, shrouded in the legend of an ancient lizard. There, she meets scientist Nikolai and his father, Igor, obsessed with finding the mythical lizard. Nikolai's experiment with infrasound sonar spirals out of control, killing Igor and Masha, who was trying to save her lover. Having lost Masha, Nikolai discovers faith—will he be able to resist death?