Investigator Lennox just can't stay out of trouble. Lennox is looking for legitimate cases - anything's better than working for the Three Kings, the crime bosses who run Glasgow's underworld. So when a woman comes into his office and hires him to follow her husband, it seems the perfect case. And, unusually for Lennox, it's legal. But this isn't a simple case of marital infidelity. When the people he's following start to track him, once more Lennox must draw on the violent, war-damaged part of his personality as he follows this trail of dead men and broken hearts.