"Let us see _weather_ it is or not," Allenby said. * * * * * Burton brought out a steel tape-measure. The hole was four and three-eighths inches across. It was perfectly circular and about sixteen inches long. And four feet above the ground. "But why?" said Randolph. "Why should anyone bore a four-inch tunnel through a rock way out in the middle of the desert?" "Religious symbol," said Janus. He looked around, one hand on his gun. "We'd better keep an eye out--maybe we've landed on sacred ground or something." "A totem _hole_, perhaps," Allenby suggested. "Oh. I don't know," Randolph said--to Janus, not Allenby. As I've mentioned, we always ignored Allenby's puns. "Note the lack of ornamentation. Not at all typical of religious articles." "On Earth," Gonzales reminded him. "Besides, it might be utilitarian, not symbolic." "Utilitarian, how?" asked Janus. "An altar for snakes," Burton said dryly. "Well," said Allenby, "you can't deny that it has its _holy_ aspects." "Get your hand away, will you, Peters?" asked Janus. I did. When Janus's camera had clicked, I bent again and peered through the hole. "It sights on that low ridge over there," I said. "Maybe it's some kind of surveying setup. I'm going to take a look." "Careful," warned Janus. "Remember, it may be sacred." As I walked away, I heard Allenby say, "Take some scrapings from the inside of the hole, Gonzales. We might be able to determine if anything is kept in it...." One of the stumpy, purplish, barrel-type cacti on the ridge had a long vertical bite out of it ... as if someone had carefully carved out a narrow U-shaped section from the top down, finishing the bottom of the U in a neat semicircle. It was as flat and cleancut as the inside surface of a horseshoe magnet. I hollered. The others came running. I pointed. "Oh, my God!" said Allenby. "Another one." The pulp of the cactus in and around the U-hole was dried and dead-looking. Silently Burton used his tape-measure. The hole measured four and three-eighths inches across. It was eleven inches deep. The semicircular bottom was about a foot above the ground. "This ridge," I said, "is about three feet higher than where we landed the ship. I bet the hole in the rock and the hole in this cactus are on the same level." * * * * * Gonzales said slowly, "This was not done all at once. It is a result of periodic attacks. Look here and here. These overlapping depressions along the outer edges of the hole--" he pointed--"on this side of the cactus. They are the signs of repeated impact. And the scallop effect on _this_ side, where whatever made the hole emerged. There are juices still oozing--not at the point of impact, where the plant is desiccated, but below, where the shock was transmitted--" A distant shout turned us around. Burton was at the rock, beside the ship. He was bending down, his eye to the far side of the mysterious hole.