When a lonely old man is found murdered in his Reykjavik flat, the only clues are a cryptic note left by the killer and a photograph of a young girl's grave. Inspector Erlendur, who heads the investigation team, discovers that many years ago the victim was accused, though not convicted, of an unsolved crime. Did the old man's past come back to haunt him? As the team of detectives reopen this very cold case, Inspector Erlendur uncovers secrets that are much larger than the murder of one old man--secrets that have been carefully guarded by many people for many years. As he follows a fascinating trail of unusual forensic evidence, Erlendur also confronts stubborn personal conflicts that reveal his own depth and complexity of character.