When two skeletons are discovered from Lamentation Tarn, talented detective Mike Nash and his team have little evidence with which to work, until a surprising discovery prompts them to contact law enforcement agencies in Eastern Europe. A joint taskforce is formed to uncover a criminal network involved in prostitution, drugs and human trafficking, but Nash's preoccupation with internal politics, as well as with an attractive Russian detective, proves to be a distraction. Finally, a young victim escapes the gang's clutches, providing Nash with much needed evidence. A search of the neighbouring tarn yields further corpses and reveals an even more heinous crime. Two more bloody encounters must occur before the criminals are brought to bitter justice.