1956: Against all odds, disgraced ex-cop Victor Mason brings down the Winter Angel, New York's most brutal serial killer. Vic is a hero, but it's a mystery how one man could possibly have done what an entire police force could not.

2025: In London, Met Detective Charlie Warrington is confronted with the mutilated body of a young woman. His heart stops as he recognises the gruesome signature of a killer who was apprehended almost 70 years ago. A killer he knows only too well.

Because Vic and Charlie have a secret. The two men share one life, split across decades and oceans. When one sleeps, the other wakes. Their unique bond has made them unstoppable. Until now.

After seven decades, someone has taken up the Winter Angel's terrible mantle. And this time, history isn't just repeating itself - it's hunting them both.