'A fantastic thriller - dead-on domestic noir, full of tension and surprises. I loved it.' Lee Child 'An enthralling thriller that lives up to its chilling premise.' Renee Knight, author of Disclaimer ********** 'No one lives this way unless they want to hide something.' When Caroline and Francis receive an offer to house swap, they jump at the chance for a week away from home. After the difficulties of the past few years, they've worked hard to rebuild their marriage for their son's sake; now they want to reconnect as a couple. On arrival, they find a house that is stark and sinister in its emptiness - it's hard to imagine what kind of person lives here. Then, gradually, Caroline begins to uncover some signs of life - signs of her life. The flowers in the bathroom or the music in the CD player might seem innocent to her husband but to her they are anything but. It seems the person they have swapped with is someone she used to know; someone she's desperate to leave in her past. But that person is now in her home - and they want to make sure she'll never forget . . .