“It has heard some queer stories in its time,” replied Mr. Ludgrove with a smile. “You can form no idea of the extraordinary confessions which some of my clients force me to listen to. But I can assure you that it has heard nothing more amazing that the story which I am about to unfold to you this evening.”
“May I ask a question before you begin, Mr. Ludgrove?” said the Professor quietly.
“Certainly, pray ask as many as you please,” replied Mr. Ludgrove with a smile.
“How did you learn of my interest in this affair? So far as I am aware, it is not common property.”
“I am afraid that Inspector Hanslet was indiscreet,” replied Mr. Ludgrove. “When he first took over the case, he came here and had a long talk with me. He said then that he would put the facts before one whose powers of deduction were unrivalled. When I next saw him, he happened to mention your name, which I already knew as that of the boldest and most enterprising scientist of the age. It required very little intelligence on my part to infer that you would be interested in these extraordinary happenings, and that you were scarcely likely to accept the official explanation of them.”
“I see,” said the Professor. “Well, as it happens, your inference is correct. I am greatly interested, and I have a theory of my own as to the motive for the murders, which the police have been pleased to reject. I am all the more anxious to hear the evidence you have to put before me. There is still one more point in which I am interested. I am informed that, sometime before his death, Mr. Copperdock reported that he had met an individual known as the Black Sailor. Upon this being reported to you, you stated that you happened to have Mr. Copperdock under observation at the moment when he stated the meeting took place, and that no Black Sailor was present. Is this correct?”
“I can assure you, Dr. Priestley, that at that moment there was nobody in sight but Mr. Copperdock and myself,” replied Mr. Ludgrove simply.
“Thank you,” said the Professor. “Now, I am prepared to examine the evidence you have to show me.”
Mr. Ludgrove rose from his chair. “Will you excuse me for a few minutes, Dr. Priestley?” he said. “Before I begin my explanation, I should like to fetch certain things which I have put in a place of security upstairs. I will not keep you very long.”
He passed into the shop as he spoke, and the Professor could hear the sound of his footsteps as he climbed the stairs. The Professor, left alone in the room, proceeded to examine the titles of the books in the shelves. They were mainly botanical works, such as one might expect to find in the library of a herbalist. But here and there among them were a few volumes of general scientific interest. Dr. Priestley smiled as he saw, lying inconspicuously at the end of one of the shelves, a work he had published a year or so before, Fact and Fallacy. No doubt this had given Ludgrove the cue to his own interest in a problem so intricate as that of the Praed Street murders.
Lying next to it was a book bearing the name of an author well-known in the scientific world, which the Professor had never heard of. He took it up and began to turn over the pages with interest. His eye caught a passage dealing with one of the subtler mathematical problems raised by a particular aspect of relativity. He became absorbed in this, forgetting all about Mr. Ludgrove and his promised demonstration. So he remained for several minutes, until he had read the passage from beginning to end. Then, all at once, he became conscious that he was no longer alone in the room, that somebody was standing just inside the door, awaiting his pleasure. The Professor laid the book down, and turned on his heel, an apology upon his lips. But the words died in his throat, and he stood for an instant staring at the figure with unbelieving eyes.
It was the Black Sailor.
XXI
An Explanation
The Professor’s first startled thought concerned the manner in which the man had entered the room. He had heard no sound of his entry, and he remembered that Mr. Ludgrove had been careful to lock the door of the shop when they had come in together. His second was a sudden thrust of anxiety for Mr. Ludgrove’s safety. In the complete silence of the little room, into which no sound penetrated but the faint low rumble of the traffic outside, he listened for the sound of his footsteps above. But, even to his keen ears, the house seemed as quiet as the grave.
It was the Black Sailor who broke the silence. “Sit down, Dr. Priestley,” he said gravely. “I have much to say to you. You will recall that this is our second meeting.”
But Dr. Priestley took a step forward, and stared into the man’s face, at his jet-black beard and hair, at the scar which gleamed angrily upon his cheek. He wore a woollen cap, drawn over his face, and a blue pilot coat over his jersey. But for these details, he was dressed as he had been when the Professor had met him upon the Isle of Purbeck. And the tones of his rasping voice sent a thrill of fear through even the Professor’s determined heart.
“How did you get in here? Where is Mr. Ludgrove?” The Professor found his
