These ruins of an ancient sanctuary are still notorious - once the Druids performed human sacrifices here. The times of the servants of the ruthless Celtic gods have long since passed into the realm of legends, but... Two girls have already disappeared without a trace near the sanctuary. This is the second time Detective Harry Nelson receives an anonymous message, the author of which claims that they were sacrificed. The author of the letters is clearly obsessed with the idea of reviving the pagan cult? But is he a kidnapper and murderer? And if not, then where does he get the information? Nelson is forced to resort to the help of the famous archaeologist Ruth Galloway, who knows everything about ancient rituals...