The rock underfoot was crumbling and he had to watch where he put his feet. At the same time he fought a constant impulse to look up, watching for anything falling from above. Nothing happened. When he reached the top of the wall he was breathing hard; sweat moistened his body. There was still no one in sight. He stood on an unevenly shaped wall that appeared to circle the building. Instead of having a courtyard inside it, the wall was the outer face of the structure, the domed roof rising from it. At varying intervals dark openings gave access to the interior. When Brion looked down, the sand car was just a dun-colored bump in the desert, already far behind him. Stooping, he went through the nearest door. There was still no one in sight. The room inside was something out of a madman's funhouse. It was higher than it was wide, irregular in shape, and more like a hallway than a room. At one end it merged into an incline that became a stairwell. At the other it ended in a hole that vanished in darkness below. Light of sorts filtered in through slots and holes drilled into the thick stone wall. Everything was built of the same crumble-textured but strong rock. Brion took the stairs. After a number of blind passages and wrong turns he saw a stronger light ahead, and went on. There was food, metal, even artifacts of the unusual Disan design in the different rooms he passed through. Yet no people. The light ahead grew stronger, and the last passageway opened and swelled out until it led into the large central chamber. This was the heart of the strange structure. All the rooms, passageways and halls existed just to give form to this gigantic chamber. The walls rose sharply, the room being circular in cross section and growing narrower towards the top. It was a truncated cone, since there was no ceiling; a hot blue disk of sky cast light on the floor below. On the floor stood a knot of men who stared at Brion. Out of the corner of his eyes, and with the very periphery of his consciousness, he was aware of the rest of the room--barrels, stores, machinery, a radio transceiver, various bundles and heaps that made no sense at first glance. There was no time to look closer. Every fraction of his attention was focused on the muffled and hooded men. He had found the enemy. Everything that had happened to him so far on Dis had been preparation for this moment. The attack in the desert, the escape, the dreadful heat of sun and sand. All this had tempered and prepared him. It had been nothing in itself. Now the battle would begin in earnest.