“That certainly sounds as if it were sent to the man you are seeking.” I remarked. “Has anything come of these enquiries?”

“Well, we have not yet got the man, but a discovery was made yesterday which proves that his talk of Hull was indeed a blind. A sorter at the General Post Office in Glasgow noticed a letter addressed to Mr M. Quinlivan and marked ‘to be called for’. A warrant was at once obtained and the letter opened. It proved to be similar to the one I had found in Leicester: ‘You must give yourself up. Do not despair’ – that sort of thing. It was signed by the same person, the Reverend B. Arnold. There was again no address at the top of the letter, but the envelope was postmarked ‘London East’.”

“Have you been able to trace this man, Arnold?”

“Not so far. He calls himself Reverend, but we can find no clergyman of that name in London.”

“Perhaps he belongs to some small and obscure nonconformist Church.”

“That must be so. But all our resources have so far failed to find him.”

“You are not aware of any other discovery that Holmes has made?”

The policeman hesitated a moment before replying.

“Just one, that I know of, Dr Watson, and between ourselves, it seemed more to indicate that his mind was losing its grip than anything else. It was as we were examining the bedroom at Unwin’s boarding house. Mr Holmes had picked up a white hair from the hearth and fallen silent. I spoke to him but he did not answer. He just stared at the hair, examined it with his lens, stared at it again, and did not open his mouth for thirty minutes or more. On the train back to London, I could see that he was excited about something, but he said little, except that the murderer had made a slip, ‘a tiny, tiny slip’, he said. ‘He has been very clever, and has come within a hair’s breadth of getting clean away,’ said he, ‘but he will not evade us for much longer now.’ Then he laughed, in that odd, silent way of his. Quite frankly, Dr Watson, had it been anyone but Mr Holmes, I should have found myself another compartment to sit in at the first opportunity. One gets accustomed to Mr Holmes’s odd ways, but confined for a hundred miles or more with someone laughing to himself the whole way is almost too much for anyone to stand.”

At that moment, the shop door opened and Holmes himself appeared before us, an expression of urgency upon his features.

“Pray forgive the delay,” said he in a brisk manner. “If you will come now, I have a cab waiting outside.”

“Where are we going?” asked Lanner in surprise.

“To arrest Mr Quinlivan,” said Holmes.

There were two four-wheelers standing in the street outside. Holmes opened the door of the first one, and I was surprised to see that it already had one occupant, a thin, reserved-looking man, with short dark hair and a small beard.

“This is Mr Woodward,” said Holmes as we climbed in. “He is to assist us. Our first port of call will be Gordon Square,” he continued as the cab rattled off, “home of Mr Basil Thorne, nephew of the murdered woman. He asked me to notify him at once when I had some positive news, and I think he should be present when his aunt’s murderer is arrested.”

“You believe Quinlivan has returned to London, then?” I queried.

“I am absolutely certain of it, Watson. Has Inspector Lanner brought you up to date with the case?”

“Indeed. He informs me that you attach great significance to a hair.”

My friend chuckled to himself. “It may appear a somewhat slender thread on which to hang a case,” said he at length, “but it has proved sturdy enough for the task. It is, after all, a horse’s hair.”

“A horse’s hair!”

“Indeed. And it has led me at a merry gallop, from a small boarding house in Leicester to the present whereabouts of the most sought-after villain in England! He is a very cunning man, Watson, and if we had not found him now, I think it likely he would never have been found at all!”

No more would he say, and we travelled on in silence. As we turned into Russell Square, I observed that another four-wheeler, which had been behind us in Southampton Row, turned the same way.

“That cab appears to be following us,” I remarked. “I am certain I saw the same one in Ludgate Hill, as we left Brown’s Coffee Shop.”

“So it does,” said Holmes with a chuckle. It was clear from his tone that he knew something we did not, and Lanner glanced behind us with a frown on his face.

“I wish I knew what was afoot,” said he.

“All will be revealed shortly,” cried Holmes gaily. “Trust me, Lanner, and you could yet gain the divisional superintendent’s position you aspire to!”

With a sigh, the policeman sat back in his seat. “Very well,” said he. “We are in your hands, Mr Holmes.”

Arriving at Basil Thorne’s house in Gordon Square, Holmes, Lanner and I were shown into a richly decorated chamber, used as a study. A tall, broad-shouldered, handsome man, with firm features and a small dark moustache, Thorne listened with an expression of intense interest as Holmes quickly explained to him what had been discovered in Leicester and Glasgow.

“But what makes you think that Quinlivan is in London again?” he asked in a puzzled voice as Holmes finished. “Do you believe he’s staying with the man whose letters you found?”

Holmes nodded his head. “Yes,” said he, “the two of them are together. But I had quite forgotten Mr Woodward!” he cried abruptly, springing from his chair. “Perhaps his testimony will make matters clearer.” He hurried from the room and returned a moment later with the thin man who had travelled with us in the cab. “This is Mr George Woodward,” said he, “who has some very important information.”

For a moment the newcomer glanced about the study, as if somewhat abashed by the opulence of his surroundings. Then, at a nod from Holmes, he raised his hand and spoke with an abruptness that set my hair on end.

“That is the man,” said he, pointing at Thorne.

For a moment there was silence, then Holmes spoke.

“I should perhaps explain,” said he in an urbane voice, “that Mr Woodward is a clerk at the left-luggage office at Leicester railway station. He was on duty there on Friday morning when you deposited a bag, Mr Thorne, before catching the early train back to London.”

“He must be mistaken,” said Thorne in a tone of puzzlement. “I have never been to Leicester in my life.”

“Matthew Quinlivan was there.”

“So I understand, from what you have told me, but I fail to see the relevance of that to myself.”

“You are Matthew Quinlivan.”

“What!” we all cried as one.

“It was a very clever scheme,” said Holmes calmly, addressing Thorne, who had taken a step backwards in alarm. “You have been living above your income for some years. Two years ago, you expected your aunt to die and you ran up very large debts in anticipation of your imminent inheritance. Inconveniently for you, she did not die, and you therefore determined to take matters into your own hands. It was vital, of course, that in the event of her death no suspicion should ever attach to you, and to that end, you conceived the idea of establishing the existence of a fictitious character – Quinlivan – who would commit the crime in as obvious a manner as possible, so that there could be no doubt as to who had done it, and then vanish without trace. Knowing your aunt’s weakness for charitable causes, especially those with a religious connection, you could be reasonably confident that ‘Quinlivan’ would gain access to her, and confident also that, because of her very poor eyesight and hearing, she would not detect the imposture.”

“Nonsense!” Thorne interrupted with a cry, his voice dry and hoarse. “What of the letters Quinlivan received from the clergyman you mentioned?”

“You wrote them yourself, Thorne, to add to the air of verisimilitude surrounding the murderer’s flight.”