In this twisty psychological serial killer thriller from the New York Times bestselling author of The Girl Before , an actress plays both sides of a murder investigation. One out-of-work British actress pays the rent on her New York City apartment the only way she can: as a decoy for a detective agency, hired to entrap straying husbands. When the cops begin investigating one of her targets for murdering his wife--and potentially others--they ask her to lure the suspect into a confession. But with the actress pretending to be someone she isn't, differentiating the decoy from the prey becomes impossible--and deadly.