"But he never returned, we never found him nor his body.  I do not know what happened.  But my own misgivings about Martians date to that incident.  They never again seemed to me to be just big, gentle, harmless, rather comical creatures, even though we never had any trouble with them and they always gave us anything we wanted, once Stinky figured out how to ask for it.  I played down the incident - can't let men panic when you're a hundred million miles from home.  Oh, I couldn't play down the fact that Dr. Agnew was missing and the whole ship's company searched for him.  But I squelched any suggestion that there had been anything mysterious about it - Agnew had gotten lost among those rocks. had eventually died, no doubt, when his oxygen ran out... and was buried under sand drift or something.  You do get quite a breeze both at sunrise and sundown on Mars; it does cause the sand to drift.  So I used it as a reason to clamp down ever harder on always traveling in company, always staying in radio contact with the ship, always checking breather gear... with Agnew as a horrible example.  I did not tell that crewman to keep his mouth shut; I simply hinted that his story was unbelievable, especially as his mate was not able to back it up.  I think the official version prevailed."