With his near-fatal stabbing almost a memory, DI Bob Valentine is settling back onto the force, until one of Ayrshire's darkest secrets is unearthed. The skeletal remains of a boy, his hands and feet cable-tied, turns up during routine drainage works. He's soon identified as a missing child from the 1980s. When the remains of more children are unearthed, Valentine soon finds himself embroiled in a conspiracy linking the past and present through some of the most shocking crimes of his police career.