When two grieving strangers meet by chance in Osaka airport they uncover a disturbing connection. Jake's best friend and Mariko's twin brother each died, 6,000 miles apart, in brutal and unfathomable circumstances.

Each encountered a mesmerising, dark-haired woman in the days before their deaths. A woman who came looking for Mariko - and then disappeared.

Jake, who has carried his loss and guilt for a decade, finds himself compelled to follow the trail set by Mariko's revelations. It's a trail that weaves across continents and centuries, leading back to the many who have died - in strange and terrifying and eerily similar ways - and those they left behind: bewildered, disbelieved, yet resolutely sure of what they saw.

And, at the centre of it all, there is the same beguiling woman. Her name may have changed, but her purpose has never wavered, and as Jake races to discover who, or what she is, she has already made her next choice.

But will knowing her secret be enough to stop her?