A mysterious river island with a dark history both attracts and terrifies: once home to a pagan shrine, it later became an impregnable prison. Now they are trying to build a utopian eco-settlement there—but the past refuses to let go. Young sociologist Ekaterina arrives to conduct a census and unexpectedly meets Mikhail—the father of her child and her first love, who vanished without a trace seven years ago. The joy of their reunion is cut short by a nighttime tragedy: a murder is committed on the island. Investigator Natalia Stepankova takes charge of the case—her husband died here under mysterious circumstances a year ago. The deeper she delves into the island’s secrets, the more clearly she understands that the eco-settlement hides far more secrets than it seems at first glance. A detective melodrama with elements of mysticism about guilt, retribution, and the ghosts of the past that always return.