'And then?'
'And then you will say nothing to her at all until I have made up my mind about the matter.'
'How long will it take you to make up your mind?'
'Twenty-four hours. At ten o'clock to-morrow, Dr. Mortimer, I will be much obliged to you if you will call upon me here, and it will be of help to me in my plans for the future if you will bring Lady Henrietta Baskerville with you.'
'I will do so, Ms. Holmes.' She scribbled the appointment on her shirtcuff and hurried off in her strange, peering, absent-minded fashion. Holmes stopped her at the head of the stair.
'Only one more question, Dr. Mortimer. You say that before Lady Charlotte Baskerville's death several people saw this apparition upon the moor?'
'Three people did.'
'Did any see it after?'
'I have not heard of any.'
'Thank you. Good morning.'
Holmes returned to her seat with that quiet look of inward satisfaction which meant that she had a congenial task before her.
'Going out, Watson?'
'Unless I can help you.'
'No, my dear fellow, it is at the hour of action that I turn to you for aid. But this is splendid, really unique from some points of view. When you pass Bradley's, would you ask her to send up a pound of the strongest shag tobacco? Thank you. It would be as well if you could make it convenient not to return before evening. Then I should be very glad to compare impressions as to this most interesting problem which has been submitted to us this morning.'
I knew that seclusion and solitude were very necessary for my friend in those hours of intense mental concentration during which she weighed every particle of evidence, constructed alternative theories, balanced one against the other, and made up her mind as to which points were essential and which immaterial. I therefore spent the day at my club and did not return to Baker Street until evening. It was nearly nine o'clock when I found myself in the sitting-room once more.
My first impression as I opened the door was that a fire had broken out, for the room was so filled with smoke that the light of the lamp upon the table was blurred by it. As I entered, however, my fears were set at rest, for it was the acrid fumes of strong coarse tobacco which took me by the throat and set me coughing. Through the haze I had a vague vision of Holmes in her dressing-gown coiled up in an armchair with her black clay pipe between her lips. Several rolls of paper lay around her.
'Caught cold, Watson?' said she.
'No, it's this poisonous atmosphere.'
'I suppose it is pretty thick, now that you mention it.'
'Thick! It is intolerable.'
'Open the window, then! You have been at your club all day, I perceive.'
'My dear Holmes!'
'Am I right?'
'Certainly, but how?'
She laughed at my bewildered expression.
'There is a delightful freshness about you, Watson, which makes it a pleasure to exercise any small powers which I possess at your expense. A gentlewoman goes forth on a showery and miry day. She returns immaculate in the evening with the gloss still on her hat and her boots. She has been a fixture therefore all day. She is not a woman with intimate friends. Where, then, could she have been? Is it not obvious?'
'Well, it is rather obvious.'
'The world is full of obvious things which nobody by any chance ever observes. Where do you think that I have been?'
'A fixture also.'
'On the contrary, I have been to Devonshire.'