“It is possible that Stapleton did not know of the existence of an heir in Canada. In any case he would very soon learn it from his friend Dr. Mortimer, and he was told by the latter all details about the arrival of Henry Baskerville. Stapleton’s first idea was that this young stranger from Canada might possibly be done to death in London without coming down to Devonshire at all. He distrusted his wife ever since she had refused to help him in laying a trap for the old man, and he dared not leave her long out of his sight for fear he should lose his influence over her. It was for this reason that he took her to London with him. They lodged, I find, at the Mexborough Private Hotel, in Craven Street, which was actually one of those called upon by my agent in search of evidence. Here he kept his wife imprisoned in her room while he, disguised in a beard, followed Dr. Mortimer to Baker Street and afterwards to the station and to the Northumberland Hotel. His wife had some inkling of his plans; but she had such a fear of her husband - a fear founded upon brutal ill-treatment - that she dare not write to warn the man whom she knew to be in danger. If the letter should fall into Stapleton’s hands her own life would not be safe. Eventually, as we know, she adopted the expedient of cutting out the words which would form the message, and addressing the letter in a disguised hand. It reached the baronet, and gave him the first warning of his danger.

“It was very essential for Stapleton to get some article of Sir Henry’s attire so that, in case he was driven to use the dog, he might always have the means of setting him upon his track. With characteristic promptness and audacity he set about this at once, and we cannot doubt that the boots or chamber-maid of the hotel was well bribed to help him in his design. By chance, however, the first boot which was procured for him was a new one and, therefore, useless for his purpose. He then had it returned and obtained another - a most instructive incident, since it proved conclusively to my mind that we were dealing with a real hound, as no other supposition could explain this anxiety to obtain an old boot and this indifference to a new one. The more outré and grotesque an incident is the more carefully it deserves to be examined, and the very point which appears to complicate a case is, when duly considered and scientifically handled, the one which is most likely to elucidate it.

“Then we had the visit from our friends next morning, shadowed always by Stapleton in the cab. From his knowledge of our rooms and of my appearance, as well as from his general conduct, I am inclined to think that Stapleton’s career of crime has been by no means limited to this single Baskerville affair. It is suggestive that during the last three years there have been four considerable burglaries in the west country, for none of which was any criminal ever arrested. The last of these, at Folkestone Court, in May, was remarkable for the cold-blooded pistolling of the page, who surprised the masked and solitary burglar. I cannot doubt that Stapleton recruited his waning resources in this fashion, and that for years he has been a desperate and dangerous man.

“We had an example of his readiness of resource that morning when he got away from us so successfully, and also of his audacity in sending back my own name to me through the cabman. From that moment he understood that I had taken over the case in London, and that therefore there was no chance for him there. He returned to Dartmoor and awaited the arrival of the baronet.”

“One moment!” said I. “You have, no doubt, described the sequence of events correctly, but there is one point which you have left unexplained. What became of the hound when its master was in London?”