A member of Captain White’s army, Sproule is, along with the kid, one of the few survivors of the massacre inflicted by the Comanches on White’s army. Though wounded in the arm, Sproule manages to trek through the desert alongside the kid. The two encounter merciful Mexican bandits, but one night Sproule is attacked by a vampire bat. He dies in a wagon en route to an unnamed Mexican town, and the kid is arrested by Mexican soldiers soon after.