But how did this person know where I am staying asked Sir Henry. I do not know," said Holmes. "But you said that two strange things have happened. What is the order strange thing? I have lost a boot,' said Sir Henry. Someone has stolen one of my boots at the hotel. "One of your boots? Holmes. asked "Someone took only one?" Yes, answered Sir Henry. "The boots are new. I bought them yesterday and l have never worn them. But why take only one? That is a very good question,' said Holmes. "I would like to visit your hotel. Perhaps I shall find the answer. "Then, please join us for lunch,' said Sir Henry. Now if you will excuse me, I have some other business. Shall we meet at two o'clock for lunch at the Northumberland Hotel? "We shall come at two," said Holmes. Sir Henry Baskerville and Dr Mortimer left the house and walked along Baker Street. Sherlock Holmes watched them through the window of his study. "Quick, Watson, we must follow them,' said Holmes. I put on my hat and followed Holmes into the street. Why are we following them?' I asked in surprise. "Because, my dear Watson, someone else is also follow. ing them," said Holmes. Look! There is the man. There in that cab! I looked where Holmes was pointing. A horse-drawn cab was moving slowly along the street. A man with a black beard was sitting in the cab. He was watching Sir Henn and Dr Mortimer as they walked towards Oxford Street.
The man with the black beard turned round as Holmes pointed at him. He saw us and shouted to the cab driver Drive! Drive quickly!' The cab driver whipped the horse and the cab disappeared round a corner. "I think we have the answer to one of our questions, said Holmes. That man with the black beard followed Sir Henry to the Northumberland Hotel. He is the man who sent the letter.