In the dachas lost among the endless Meshchera swamps, an eleven-year-old girl disappears without a trace. Then her parents die tragically. The incident is not uncommon for these places, but the circumstances preceding it are shrouded in dark mystery. The trouble is that they are known only to one boy, who himself barely remains alive, unwittingly caught in the cycle of a revived ancient curse. Despite the horror of what happened, he understands that all this is just the tip of the iceberg. The real nightmare is hidden much deeper and sooner and later, he will have to face it firsthand. Step by step, he will be forced to plunge into the yawning depths of the underworld and learn not only the terrible secrets of the family of the disappeared girl, but also meet the monstrous mistress of the local swamps - the swamp witch Ushma, whose sleep was interrupted by the bloody atrocities of a cruel serial maniac...