Agent Carl Hamilton returns to Sweden after lengthy training in the United States. At the same time, Stockholm is startled by a series of terrorist attacks.

Twelve girls wake up in a secluded mansion, but they have no idea how or why they got there. They are locked in as part of a medical experiment, and if do not manage to escape, they will by die, one by one.

Viveca Sten's popular novels come to life in a mix of Nordic crime and the beautiful surroundings of the outer Stockholm archipelago.