I looked back, and saw that I had run in the wrong direction. But it made no difference. Over a whole circle around us the sand was rising, and directly between us and the _Comet_ there was a great green-brown mass. We were surrounded. We stood staring at the creatures. Spread out to full dimensions, each one made a sphere about four feet in diameter. In the center, a solid mass whose outlines were difficult to discern; and spreading out from this a hundred long, thin, many-jointed arms or legs or branches or whatever one could call them. The things were not yet definitely hostile--only their circle, of perhaps fifty yards radius, grew continually thicker and more impenetrable. Within the enclosed area, the only ripples we could see in the sand were heading outward. There was to be no surprise attack from below, at least; only one in mass. What, I wondered, might be a sign of friendship, to persuade them to let us go. * * * * * And then the circle began to close in. The things rolled over and over on themselves, like gigantic tumbleweeds. At one point, to the right of the direct route to the _Comet_, the line seemed thinner. I pointed the place out to Garth. "Break through there, and make a run for it." We charged into the midst of them with swinging blades. The very suddenness of our rush carried us half-way through their midst. Then something had my legs from behind. I almost fell, but succeeded in turning and cutting myself free. The creatures from the other side of the circle must have made the hundred yards in four or five seconds. And the rest had now covered the breach in front. It was hopeless. And so we stood back to back, hewing out a circle of protection against our enemies. They seemed to have no fear, and in spite of the destruction our blades worked among them, they almost overcame us by sheer numbers and weight. It was a case of whirling our swords back and forth interminably in the midst of their tentacles. Against the light, the long arms were a half-transparent brown. Our swords broke them in bright shivers. Formed from the predominant silicon of the planet, the creatures were living glass! For perhaps a quarter of an hour we were in the thick of them, hewing until I thought my arms must fall, slashing and tearing at the ones that had got underfoot and were clamping their tentacles around our legs. Only for the space-suits, we should have, by this time, been overpowered and torn into bits--and yet these garments could not be expected to hold indefinitely. * * * * * But at last there was a breathing space. The crippled front ranks dragged themselves away, and there was left around us a brief area of sand, covered with coruscating splinters of glass. Garth got the breath to say something or other encouraging. It was like old days at school.