Old Metairie Mystery Book Club - Nobody’s Fool by Harlan Coben

Sami Kierce, a young college grad backpacking in Spain with friends, wakes up one morning, covered in blood. There's a knife in his hand. Beside him, the body of his girlfriend. Anna. Dead. He doesn't know what happened. His screams drown out his thoughts -- and then he runs. Twenty-two years later, Kierce, now a private investigator, is a new father who's working off his debts by doing low level surveillance jobs and teaching wannabe sleuths at a night school in New York City. One evening, he recognizes a familiar face at the back of the classroom. Anna. It's unmistakably her. As soon as Kierce makes eye contact with her, she bolts.