"The Ranger's Apprentice" series, written by John Flanagan, is a young adult fantasy novel that follows the journey of Will Treaty, a young boy who is chosen to be a Ranger, a spy and warrior in the kingdom of Araluen. The first book in the series, "The Ruins of Gorlan," sets the stage for the adventures of Will and his companions as they navigate the complexities of medieval politics, magic, and war.