When the body of a beautiful woman is pulled from the black waters of a remote moorland lake by police frogmen, Detective Inspector Mark Hobson is faced with a highly complex case. Given the fact that the victim was universally detested and that a great many people will be glad to see her dead it is clear from the outset that nothing about this case will be straightforward. His efforts to solve this mystery draw Hobson into a 20 year old family tragedy and cause him to re-examine the case of a local man tried and convicted of child sex offences a decade before but which still has dark secrets to reveal. Hobson's task becomes immeasurably more difficult when the lives of his wife and unborn child become dangerously at risk, and his judgement is seriously questioned by another investigating officer.