Matt Dillon gets a letter from Mike Yardner, a woman whom he "knew" many years ago. When he arrives, he learns that her daughter, Beth has been abducted by one of Geronimo's War Chiefs known as Wolf. She also tells him that he is her father.
So with an Army Scout named Chalk they try to find her. Dillon decides to take two Indian boys who are related to Geronimo, who are presently being held by the Army, with him to trade for his daughter.
But General Myles wants to execute them, so with Mike and Chalk's help Matt gets them and goes out into the desert to find Geronimo's camp.