It's a peaceful Sunday evening in suburban Glasgow until a battered van pulls up to one home and disgorges a group of armed men in balaclavas. They smash into the house and hold the family at gunpoint and demand millions of pounds. Baffled, the assembled people protest that they don't have access to that sort of money.

The attackers kidnap the elderly grandfather and storm off into the night. Now senior policewoman Alex Morrow has been summoned to investigate the case. But there are so many mysteries. Who were the men? And why did they think a normal household concealed untold riches? The family is certainly not talking. But as she starts to delve deeper, she realizes that there are dark secrets all around...