Retired detective Frank Marshal lives in a remote part of Snowdonia with his wife Rachel who is suffering from dementia. When Frank and his grandson Sam witness a coach crash, the hero of the hour, a wealthy local landowner Ben Carver, seems desperate not to be in the spotlight and that seems suspicious.

Police are contacted by a woman claiming that the man she has seen on the news is not Ben Carver but her husband Daniel Owen who went missing several years earlier. Frank and his friend Annie, a retired Crown Court Judge, begin to investigate as they unravel the dark secrets of Ben Carver’s life.

Can Frank and Annie uncover the sinister truth behind the true identities of the two men who bear a more than uncanny resemblance to each other.