Colwyn, looking out into the passage, could hear or see nothing to account for the sound that had startled him into wakefulness. The candle by his bedside gave a feeble glimmer which did not reach to the door, and the passage was as dark and silent as the interior of a vault. The stillness and blackness seemed to float into the bedroom like a cloud. But he was certain he had not been mistaken. A door had been unlocked somewhere in the darkness, and it had been unlocked by human hands. Who had come to that deserted wing of the inn in the small hours, and on what business? He decided to explore the passage and find out.
He left the door of his room partly open while he donned a few articles of clothing, and pulled a pair of slippers on his feet. He glanced at his watch, and noted with surprise that it wanted but a few minutes to three o'clock. He extinguished his candle and, taking his electric torch, crept silently into the passage.
He recalled the arrangements of the rooms as he had observed them the previous afternoon. There were three more bedrooms adjoining his, all empty. On the other side of the passage was the lumber room opposite, next came the room in which Ronald slept, then the dead man's room, and finally the sitting-room he had occupied. The door of the sitting-room opened not very far from the head of the stairs.
Colwyn first examined the bedrooms on his side of the passage, stepping as noiselessly as a cat, opening and shutting each door without a sound, and scrutinising the interiors by the light of his torch. They were empty and deserted, as he had seen them the previous afternoon. On reaching the end of the passage he glanced over the head of the staircase, but there was no light glimmering in the square well of darkness and no sound in the lower part of the house to suggest that anybody was stirring downstairs. He turned away, and made his way back along the passage, trying the doors on the other side with equal precaution as he went. The first three doors—the sitting-room, the murdered man's bedroom, and Ronald's bedroom—were locked, as he had seen them locked the previous afternoon by Superintendent Galloway, who had carried the keys away with him until after the inquest on the body.
The lumber room at the other end of the passage had not been locked, and the door stood ajar. Colwyn entered it, and by the glancing light of the torch looked over the heavy furniture, mouldering linen, and stiffly upended bedpoles and curtain rods which nearly filled the room. The clock of a bygone generation stood on the mantel-piece, and the black winding hole in its white face seemed to leer at him like an evil eye as the light of the torch fell on it. But nobody had been in the room. The dust which encrusted the furniture and the floor had not been disturbed for months.
Colwyn returned, puzzled, to his own room. Could he have been mistaken? Was it possible that the sound he had heard had been caused by the door of the lumber room swinging to? No! the sound had been too clear and distinct to admit the possibility of mistake, and it had been made by the grating of a key in a lock, not by a swinging door. He stood in the darkness by his open door, listening intently. Several minutes passed in profound silence, and then there came a scraping, spluttering sound. Somebody not far away had struck a match. Looking cautiously out into the passage, he saw, to his utter amazement, a gleam of light appear beneath the door in which the dead man lay. The next moment the gleam moved up the line of the door sideways, cutting into the darkness outside like a knife. The gleam became broader until the whole door was revealed. Somebody inside was opening it. Even as he looked a hand stole forth from the aperture through which the light streamed, and rested on the jamb outside.
Colwyn was a man of strong nerves, but that sudden manifestation of light and a human hand from a sealed death chamber momentarily unbalanced his common sense, and caused it to swing like a pendulum towards the supernatural. He would not have been surprised if the light and the hand had been followed by the apparition of the murdered man on the threshold, demanding vengeance on his murderer. The feeling passed immediately, and with the return of reason the detective stepped back into his room, closed his door quietly, and watched through a knife's edge slit for the visitor to the death chamber to appear.
The door of the dead man's room opened gently, and the face of the innkeeper's daughter peered forth into the darkness, her impassive face, behind which everything was hid, showing like a beautiful waxen mask against the light of the candle she held in her hand. Her clear gaze rested on Colwyn's door, and it seemed to him for a moment as though their glances met through the slit, then her eyes swept along the passage from one end to the other. As if satisfied by the scrutiny that she had nothing to fear, she stepped forth from the death chamber, closed and locked the door behind her, withdrew the key, walked swiftly along the passage to the head of the stairs, and descended them.
Colwyn opened his door and followed her. He paused outside to pick up the boots which he had placed there to be cleaned, and carrying them in his hand, ran quickly to the head of the stairs. Looking over the landing, he saw the girl reach the bottom of the stairs and turn down the passage towards the back door, still carrying the lighted candle in her hand.