Second Stage Lensmen by E.E. Smith

This killing made Kinnison ill; physically and mentally sick. It was ruthless, cowardly murder. It was worse than stabbing a man in the back; the poor devils didn't have even the faintest shadow of a chance. Nevertheless he did it.

When he had first invaded the stronghold of the Wheelmen of Aldebaran I, he had acted without thinking at all. Lensmen always went in, regardless of consequences. When he had scouted Jarnevon he had thought but little more. True -- and fortunately -- he took Worsel along; but he did not stop to consider whether or not there were minds in the Patrol better fitted to cope with the problem than was his own. It was his problem, he figured, and it was up to him to solve it.