Alice Lake lives an unconventional life in a seaside town on the East Yorkshire coast. One day she notices a man on the beach underneath her house. A man who has no memory. He can't remember his name or his address and he has no idea what he's doing in Alice's town or how he got there. In London, Lily Monrose is desperate to locate her husband. Herself and James are newly married after a whirlwind romance but a few days after returning from their dream honeymoon, James goes out to work one morning and doesn't return. In Kent, Shona Kelly is starting to worry about her ex-husband, Tom. He didn't come to collect the children on Saturday morning and no-one has heard from him since he left work on Thursday evening. Alice, Lily and Shona all have one thing in common; the man on the beach. But who is he and can he be trusted?