Pa was in th' Rangers, an' he had this run-in with some Comanches "Anse's eyes were suddenly bleak, and Drew remembered the few stark sentences the Texan had once spoken to explain his reason for being in the army a return to a frontier ranch to find nothing left, nothing he wanted to remember, after the Comanches had swept across the countryside.
Drew was remembering what the Texan had said for his reasons to be in the army.