Dorothy Martin and her husband, retired Chief Constable Alan Nesbitt, have just visited Buckingham Palace, where Alan was awarded the George Cross, when they and a friend, retired Chief Inspector Jonathan Quinn, stumble across the body of a young girl hidden in St James's Park. Wondering what led to the unfortunate girl's demise, Dorothy can't help but get involved in the case when Jonathan calls the next day and admits he knew who the victim was.