“My bedroom is immediately above the floor of the house which is occupied by Miss Carmina and her nurse. Having some little matters of my own to settle, I was late in taking possession of my room. Before the lights on the staircase were put out, I took the liberty of looking down at the next landing.
“Do you remember, when you were a child learning to write, that one of the lines in your copy-books was, ‘Virtue is its own reward’? This ridiculous assertion was actually verified in my case! Before I had been five minutes at my post, I saw the nurse open her door. She looked up the staircase (without discovering me, it is needless to say), and she looked down the staircase—and, seeing nobody about, returned to her rooms.
“Waiting till I heard her lock the door, I stole downstairs, and listened outside.
“One of my two fellow-lodgers (you know that I don’t believe in Miss Carmina’s illness) was lighting a fire—on such a warm autumn night, that the staircase window was left open! I am absolutely sure of what I say: I heard the crackle of burning wood—I smelt coal smoke.
“The motive of this secret proceeding it seems impossible to guess at. If they were burning documents of a dangerous and compromising kind, a candle would have answered their purpose. If they wanted hot water, surely a tin kettle and a spirit lamp must have been at hand in an invalid’s bedroom? Perhaps, your superior penetration may be able to read the riddle which baffles my ingenuity.
“So much for the first night.
“This afternoon, I had some talk with the landlady. My professional avocations having trained me in the art of making myself agreeable to the sex, I may say without vanity that I produced a favourable impression. In other words, I contrived to set my fair friend talking freely about the old nurse and the interesting invalid.
“Out of the flow of words poured on me, one fact of very serious importance has risen to the surface. There is a suspicious canister in the nurse’s possession. The landlady calls the powder inside, medicine. I say, poison.
“Am I rushing at a fanciful conclusion? Please wait a little.
“During the week of delay which elapsed, before the lodger in possession vacated my room, you kindly admitted me to an interview. I ventured to put some questions, relating to Teresa’s life in Italy and to the persons with whom she associated. Do you remember telling me, when I asked what you knew of her husband, that he was foreman in a manufactory of artists’ colours? and that you had your information from Miss Carmina herself, after she had shown you the telegram announcing his death?