All at once his right hand came upon an obstacle immediately in front of him. It was either the blind end of the tunnel or a door. His heart sank as the thought crossed his mind that the tunnel, so long in disuse, might have been bricked up. But moving his hand over the obstructing surface he felt that it was of wood, and in a moment he touched something cold that projected an inch or two towards him. He pressed it gently, pushed it, tried to lift it, then bore down upon it; it yielded suddenly, and from the other side came the unmistakable click of a latch. He held his breath, waiting motionless for more than a minute, fearful lest the sound should have been heard by someone on the other side. All was still as death. Keeping the latch depressed, he pushed the door gently, then more firmly. There was no yielding. Again his heart sank; was the door bolted on the inside? Had he come thus far only to be baulked at last? But doors might open outwards as well as inwards. He pulled gently at the catch, and stopped with a start, for he heard the dreaded creak of a hinge. The door had begun to open towards him; through the inch-wide opening a draught of cold air played upon his face.
Had the creak been heard? He waited, listening. The silence was still unbroken. Then he began to pull the door towards him by almost infinitesimal degrees, and with every least movement there was a faint creak that sent a thrill through him. Yet it was better to risk many slight and interrupted sounds than one loud and prolonged; and he continued, lessening the strain on the hinges by giving an upward pressure upon the catch.
It seemed an age before the door was sufficiently open to allow him to wriggle through. He waited again; then moved slowly and warily forward, to find within a few paces that his foot was arrested by another step. He had come to a staircase. This time the flight wound round and round, and as he rose higher a glint of moonlight fell through a narrow slit in the right-hand wall; he must be on a winding stair within the tower. He left the dim light behind and came again into inky blackness; then, at another turn, another slit gave entrance to the pale beam. At last, after mounting until it seemed that his winding course would never end, he came into open air and full moonlight; he was on the roof of the tower. Before stepping out from the shelter of the stairway he glanced eagerly to right and left. The roof was vacant. It was hexagonal in shape. He wondered whether it was overlooked by other towers. Dropping on his knees, he crawled under cover of the wall that intercepted the moonlight, and made his way thus to the parapet. With relief he saw that the other towers were no higher, but apparently indeed a few feet lower. Completing the circuit of the roof, he came to another stairway immediately opposite the one he had just left. He entered cautiously, and found that this also was a winding stair, differing from the other only in the fact that there were no patches of light from slits in the wall. He went down step by step, quietly, until at a turn he was brought to a sudden pause by the sight of a small lamp burning in a niche opposite a heavily-barred door. For a minute he stood still; then stepped silently down until he came to the door. He listened; he ventured to place his ear against the wood: there was no sound. Waiting for a brief space, he hovered between advancing and retiring; then, with quickening breath, he moved on past the door until he came to the foot of the staircase.