This hallway curved not far from the man in one direction, although the other side ran straight for about twenty feet before being closed off by a door similar to the one he had removed. Around the bend floated faint noises suggesting high-pitched conversation, although they came from too far away to reveal the nature of their origin. The tall man kept one eye cocked warily in that direction.
After a few minutes, certain sounds seemed to draw nearer. The cluttering "talk" faded, but he could hear more plainly a hushed scuffling that could have been caused by many feet taking short, hurried steps.
The man released his foothold and slid smoothly below the floor level just as moving shadows appeared at the bend of the corridor. He dropped down the column through four more unlighted levels, reaching an atmosphere that held a blend of machine oil along with its other odors.
Light filtered upward with the air currents. Somewhere below was a very bright level, whence came the rhythmic throb of heavy machinery. This did not resemble the sounds of a spaceship, nor yet a Terran factory, but some considerable work was being carried on. He groped out in the darkness for a foothold, got the other foot over, and wearily pushed himself away from the column.
He was on a level so dim that he touched the edge of the floor opening with his toe to make sure of its location before moving off along the corridor.
In the darkness, he went more slowly than before, but made better time than looked possible. Under the circumstances, he reassured himself by stretching out his left hand every few seconds to touch the smooth wall. He walked normally, though not noisily, and his sense of direction was extraordinarily good.
About a hundred yards along a corridor that seemed not to have a single bend or corner, he slowed his pace doubtfully. A few steps more brought him to another closed door. This one, however, yielded to his shove, swinging back to reveal a stretch of tunnel with a bare minimum of illumination oozing from widely spaced ceiling fixtures. Here, he could sense side doorways his fingers had usually missed along the darker stretch.
He had gone another hundred yards and finally passed two cross corridors, before he was again obliged to stop and rest. He slumped against the side wall, favoring his right arm and gazing dully before him.
A few steps further along was one of the typical elliptical doorways. Through this one, some light was reflected to the wall of the corridor. The man stared at it in the way anyone in the dark will turn his eye to light. After several minutes, he moved toward it as if impelled by idle curiosity.
Reaching the opening, he hesitated. A strange expression flickered over his face. The decision to look or not to look was causing him great uneasiness. Finally, he stepped forward and entered a small chamber.