For a few moments the newcomer nosed around the remains of the carnivore’s feast, and devoured the larger fragments. Then it appeared to look around as though for more, evidently saw the cave, and came rippling toward it, to Cunningham’s pardonable alarm.

He was totally unarmed, and while the centipede had just showed itself not to be above eating carrion, it looked quite able to kill its own food if necessary. It stopped, as the other investigator had, a dozen yards from the cave mouth; and like the other, elevated itself as though to get a better look. The baseball-sized black “eyes” seemed for several seconds to stare into Cunningham’s more orthodox optics; then, like its predecessor, and to the man’s intense relief, it doubled back along its own length and glided swiftly out of sight.

Cunningham again wondered whether it had detected his presence, or whether caves or darkness in general spelled danger to these odd life forms.

It suddenly occurred to him that, if the latter were not the case, there might be some traces of previous occupants of the cave; and he set about examining the place more closely, after a last glance which showed him the two men still at work jacking up the hull.

There was drifted dust even here, he discovered, particularly close to the walls and in the corners. The place was bright enough, owing to the light reflected from outside objects, to permit a good examination — shadows on airless worlds are not so black as many people believe — and almost at once Cunningham found marks in the dust that could easily have been made by some of the creatures he had seen. There were enough of them to suggest that the cave was a well-frequented neighborhood; and it began to look as though the animals were staying away now because of the man’s presence.