Almost at the same time, events occur that seem to be in no way connected with each other: a ferry sailing from Norway to England crashes in the North Sea, and in the city of Aberdeen two mysterious murders of women occur, committed as if in accordance with some something terrible ritual. A poisonous snake is left on the body of each of the victims.

But it gradually becomes clear that a connection still exists.

London detective Kate Beauchamp will have to conduct the investigation and solve the crimes. The circle of suspects is very wide, and only when Kate comes face to face with the killer and almost becomes his victim does she discover the incredible truth.