But he couldn't hear them out there. They should have reached the door by this time. He frowned, then drew out the short-wave scanner disc. He pressed the stud and tiny coils hummed to life. He moved the sliding sheathes around the rim and at last a thought-impression came through--a jumble of them. Ketrik knew his pursuers were standing on the stairs, hesitant and a bit frightened, staring at the metal door. Then a stronger impression came out of the thought-jumble as one of the Guards spoke. "Shall we go ahead? We can burn through the door." "Enter that place?" came an answer, and Ketrik felt the mental shudder that came with the words. "I'd sooner go unarmed into a den of _hellas_!" Other thoughts agreed. Ketrik grinned there in the dark. He knew now, that somewhere beyond him must be the lair of Dar Vaajo's _Entity_, and these men were deathly afraid of it. Finally another thought stabbed through. "Very well. There's no retreat for him now anyway. We'll wait here, but one of you hurry to the palace and bring Dar Vaajo!" Ketrik acted quickly then. He found the lights, saw that he was in a small metal-walled room. On the opposite side was another door, and near it was a tall case containing half a dozen protective suits. He hurriedly donned one. It wasn't hard to guess what they were for. The suit itself was of light mesh-beryllium, topped by a heavy _crystyte_ helmet. Again he brought his weapon into play, destroyed the other five suits. Let Vaajo come! He would hardly dare enter this den without protective gear! But even within the suit Ketrik didn't feel quite safe. He still remembered the power of the thing he had felt the previous night. His stomach turned over in a frightened yawn as he stepped through the opposite door. VIII He was on a wide balcony. Near at hand was a tele-vise, a control-studded panel, and other complicated machinery. Overhead, seeming so near he could almost touch it, the great laboratory dome stretched out and away in its vast curve. While below ... was emptiness. Now for the first time he realized the gigantic proportions of this building. A hundred feet below he saw bare floor. Probably twice that distance away, straight across from him, he could make out the opposite wall. There was nothing more, nothing in all that maw of space. Peering at the walls, he saw strange instruments protruding. Short and tubular, literally thousands of them reached from the floor to the height of this balcony, stretching away across the walls as far as he could see. Ketrik thought he knew what they were--but he had to be sure.