Just hours before Apollo 11 landed on the moon on 20 July 1969, young Australian pop star Cathy Wayne was shot dead on stage while performing as part of the troupe Sweethearts On Parade for American Marines in Vietnam. Yet Cathy hadn’t been killed by the enemy — she’d been gunned down by one of the very soldiers who she’d travelled half way around the world to entertain. But who shot Cathy and why?