Bellingham had come up to see him late one night, and was entertaining him with an interesting account of the rock tombs of Beni Hassan in Upper Egypt, when Smith, whose hearing was remarkably acute, distinctly heard the sound of a door opening on the landing below.
"There's some fellow gone in or out of your room," he remarked.
Bellingham sprang up and stood helpless for a moment, with the expression of a man who is half incredulous and half afraid.
"I surely locked it. I am almost positive that I locked it," he stammered. "No one could have opened it."
"Why, I hear some one coming up the steps now," said Smith.
Bellingham rushed out through the door, slammed it loudly behind him, and hurried down the stairs. About half-way down Smith heard him stop, and thought he caught the sound of whispering. A moment later the door beneath him shut, a key creaked in a lock, and Bellingham, with beads of moisture upon his pale face, ascended the stairs once more, and re-entered the room.
"It's all right," he said, throwing himself down in a chair. "It was that fool of a dog. He had pushed the door open. I don't know how I came to forget to lock it."
"I didn't know you kept a dog," said Smith, looking very thoughtfully at the disturbed face of his companion.
"Yes, I haven't had him long. I must get rid of him. He's a great nuisance."
"He must be, if you find it so hard to shut him up. I should have thought that shutting the door would have been enough, without locking it."