Twelve-year-old Bacho is captured by Spaniards in the late 1700’s during a failed Lipan raid. The mission priests try to make him feel welcome, but Bacho is determined to escape to find his parents. Aponi, a motherless girl who is Lipan from another band and loves her life at the mission, befriends Bacho. He is comforted by the fact that she speaks his language.
Twice Bacho tries to escape and twice he is brought back to Mission Concepcion, just outside of San Antonio. He rails against the routine life there, where he must endure a boring job, daily visits to the church to hear sermons and receive lessons. He dislikes the strange food, the ugly clothes, and mission life in general.
Aponi teaches him some Spanish, which makes his life more bearable, but he still harbors plans to escape. Before he strikes out on his own the third time, he decides to speak with Father Carlos, the priest in charge, who befriended him from Day One. He and the old padre come to somewhat of a new understanding of the culture of the other.
Bacho rides away from the mission, intent on finding his band of Lipan Apaches and hopefully, his parents. A year later, under different circumstances, Bacho returns to Mission Concepcion. He reunites with Aponi, who is tall and very pretty now. Will he stay or will he leave again?