Soldier Dog by Sam Angus is a young adult novel set during World War I. It follows 14-year-old Stanley, who runs away from home and enlists in the army to find his brother, Tom. Stanley is assigned to the Messenger Dog Service, caring for and training dogs that deliver messages in the midst of battle. While in France, Stanley is devastated by the death of his first dog, Bones, and later discovers that his own dog, Soldier, has been enlisted as well. As the war intensifies, Stanley risks everything to reunite with Tom, even as he faces the horrors of combat and the loss of loved ones. The novel explores themes of family, perseverance, and the emotional toll of war.