Boyd and the cold case team investigate the unsolved murder of a World War 2 conscientious objector. In 1948 George Western was found in his living room with a nine-inch nail through his head. When his grandson Adam finds new evidence and organises a media campaign, the case is reopened. Then the body of elderly William Davis is found in similar circumstances. And Grace uncovers the identical killing of Norman Taylor in 1961. The team discovers that Taylor and Western were in the same regiment during the war and trace surviving members to try to solve the murders. (thetvdb.com)