The case is cold and no break through happens until one day in 2006 police receive an anonymous letter. The writer explains that he saw Michael Ross in a Kirkwall public toilet just before the murder. The youngster was carrying a gun and had a balaclava on top of his head; he swears when he notices the witness looking at him.
Police discover that the witness is William Grant. He has kept silent for 12 years as he was too scared to speak out. But the knowledge and guilt weighs heavily on him until he decides to write to the police.
Police then find out that Michael Ross is now a hero - he has made a new life in the army and has no previous convictions. But because of the new crucial information and Grant as a witness, Michael Ross is finally arrested in May 2007 for the cold blooded murder committed 13 years before.