Preble stood up and let go with his ultramodern fast-firer. For a few seconds, as he played the weapon's muzzle like a hose, the Shadow Men were obscured by the cloud of kicked-up sand. The sand fell at once, of course--and the Shadow Men were coming directly on! Moreover, there was a grimmer note in our walkie-talkies. "One fast-firer at each cardinal point of the compass," I said. Marines in action are something to see. In a split second the Shadow Men from all sides were being warned by bullets. But they came right on. "No other choice," I said quietly. "Shoot into them. Fire at will!" Thousands of steel-jacketed slugs poured into the Shadow Men. But not one fell, and not for so much as an instant did they hesitate in their advance. Now other men had fallen back so that four concentric circles of Shadow Men closed in on us. They were quite close when they halted. I was just preparing to order our new explosives to be hurled among them, when, directly in front of me, a shadow detached itself from other shadows. It strode forward a few paces and halted. The clumsy arms seemed to gesticulate. The sounds of whispering came louder in our walkie-talkies. I think we all felt that in some way we were being challenged. "Someone is to go forward," I said. "I don't know what it wants, but--Hold your fire, now--not that it seems to be worth much!" I rose and started forward, conscious that there wasn't a movement among the marines, nor among the Shadow Men. I wondered as I approached the foremost shadow, how we would make ourselves understood to each other. The other entity must have some idea or there would be no suggestion of a parley. I must have been halfway there when I was aware of running footfalls behind me. I didn't turn--and by failing to turn I saved my own life at the expense of PFC Yount's. The footfalls were right behind me, but I wasn't expecting what happened. Arms went around my legs in as neat a tackle as ever a leatherneck footballer pulled. I was thrown on my face so hard I couldn't breathe. I don't remember when I've been downed so hard. By the time I got to my knees Yount was almost in contact with the detached shadow. He had a trench knife in his hand; drew it right after tackling me. I could see everything that happened. PFC Yount flung himself straight at the shadow. I saw him disappear _into_ the shadow, emerge on the other side. But there was a difference: _he went in a marine in full battle dress; he came out a completely articulated skeleton_. He had been stripped of clothes, shoes, weapons, skin, flesh and life--so quickly that his forward impetus carried his skeleton on through the shadow. [Illustration: He went in a Marine in full battle dress; he came out a skeleton....] Now four marines were beside me. A growl rose from the others. I had to yell at them, over my shoulder: "Stand fast! Do you want the same thing to happen to you?" The four men beside me--I didn't look to see who they were--simply waited.