Twenty years after John Costello and his girlfriend were attacked by the deranged 'Hammer of God' killer, a new spate of seemingly random and unrelated murders starts. After the attack and subsequent death of his girlfriend, John withdrew from society, emerging only to work as a crime researcher for a major newspaper. No-one knows more about serial killers than him, and soon John discovers a complex pattern linking the current murders. But could this knowledge threaten his life? The Anniversary Man is an edge-of-the-seat read from R. J. Ellory, the author of A Quiet Belief in Angels, City of Lies and A Simple Act of Violence.