Each night I ventured a little farther. The artificial lights burned low. All was quiet. The luminous rock walls stared out from among the cavern furnishings. I walked steadily. I was getting used to the planet's stronger gravity. I was learning to like the sandals they had given me to wear, cushioned with shreds of sponge-tree vegetation.

Tonight as always I walked to the right from the arch, through one of Tomboldo's rooms, and on past the storage rooms. The way opened into a long amber-lighted tunnel. The city branched off in little tunneled avenues from this passageway. Would Campbell be found on guard tonight—this way—or this way—or—

I heard light footsteps, sounds of two persons somewhere in the distance. I moved back toward Tomboldo's part of the cave to wait until the ways had cleared.

Two men were coming through the corridor, conversing in low whispers.

I moved back into the shadows, scarcely breathing.

The glow of amber light from the corridor revealed them, silhouetted. The taller man was driving the smaller one ahead of him, threatening him with a short-bladed knife.

They slowed their steps. Their low whispers were audible.

"If you breathe a word I'll rip you." The agitated words of the tall guard, Gravgak. The light revealed the lines of green-and-black diamonds painted on his thighs.

The smaller man, also a guard, muttered, "Have I ever told anything?"

"You understand, then," said Gravgak. "If anything happens, you'll swear there was an intruder—one of the savages."