Allie knows who she is. She doesn't mind being so predictable. She has a habit of skipping breakfast, being way too early, correcting people's grammar, and always leaving something behind. Phone chargers, sweatshirts, dishes, books, and the occasional ex-boyfriend. She often finds the items she leaves behind, and usually when and where they are needed most. There is no explanation for the serendipity; she can't seem to figure out how the items find their way back. It's a quirk she long ago stopped being surprised by. This time, though, there's been a murder, a murder her best friend is Lead Detective on -and she is slowly becoming the prime suspect. She fears she may have left behind the only thing she has that can prove her innocence - and she doesn't know if or when it will reappear.
Detective Louise Highcroft's first investigation is an open and shut case. The murderer has confessed, even led them too the body, there's no chance of him getting off in court. Its a fantastic start to her career. Her colleagues are envious and her superiors think she's marvellous, but she is troubled.
When another girl is reported missing, Louise can't accept the police view that she's a runaway starts thinking she got the wrong man.
Her search for answers puts her in conflict with her bosses, but she meets the Mental Health worker who was involved with the assumed murderer and who is convinced he's innocent. They embark on a roller coaster of a journey, putting their lives and professional reputations at risk as they work together to discover the truth.