There was no great look of decay about the body. Roberts had died here, certainly not five years ago. I was bending down over the body; I shoved at one of the shoulders and turned it over. Stricken Jan, Torrence and I stared numbed. A thin bronze sliver of metal--fin-tipped like a metal arrow--was buried in Roberts' back! Again the alert Jan was gazing at the dim, fantastic night-scene around us. Abruptly his hand gripped my arm as he gasped, "Why--good Lord--what's that? Over there--" In the blackness down the gully, perhaps a hundred feet from us, a little spiral of fire had appeared. A tiny wisp of red-green flame. It seemed to hover in the air a few feet above the rocky gully floor. Like a phantom wraith of fire, it silently leaped and twisted. "My God--it's coming toward us!" Torrence suddenly gasped. In the darkness the silent wisp of fire had swayed sidewise, and then came along the edge of the gully, a disembodied conflagration in mid-air, as though wafted by a rush of wind we could not feel. II For a moment of startled horror we stood motionless. The floating little flame seemed bounding now, just over the rocks. Bounding? Abruptly I seemed to see a dark shape of solidity under it--something almost, but not quite invisible in the blackness. A tangible thing? A creature--burning? Thoughts are instant things. I recall that in that second, I had the impression of a four-legged thing like a huge dog, bounding toward us over the rocks. The flame in which it was enveloped, had spread--it was a blob of flame, but solidity was there. All in a second. My little electro-gun was in my hand. And then from beside me, Torrence fired--his flash with a whining sizzle splitting the blackness of the gully with its pencil-point of hurled electrons. His hasty aim quite evidently was wild. I saw the little splash of colored sparks where his charge hit the rocks. Too high. My gun was leveled. But in that split-second, the oncoming blob of fire abruptly had been extinguished. There was only the faint blurred suggestion of the dog-like thing. It had stopped short, and then suddenly was retreating. My shot, and Jan's, followed it. In another few seconds there was no possibility of hitting it. Silently it had vanished. There was only the black silent gully around us, with the blurred crags standing like menacing dark ghosts. My instinct then, I must admit, was for us to retreat at once to our ship. In the heavy empty silence we stood blankly gazing at each other. Torrence was grim; Jan was shaking with excitement and the fear all of us felt. "You heard that whistle?" I murmured.