Pelagia's superior, Bishop Mitrofanii of Zavolzshsk, dispatches a series of emissaries to investigate the horrifying apparition of a black monk that's haunting the monastery of New Ararat on the shores of the Blue Lake, a locale as creepy as the moors of The Hound of the Baskervilles. When all end up victims of the ghostly figure, Pelagia defies the bishop and travels to the remote community to pursue the case.
