It seemed doubtful whether I should be admitted into the building if I rang the bell; and more than doubtful, if I were let in, whether the inhabitants would be able to afford me any clew to the information of which I was in search.

However, it was my duty to Monkton to leave no means of helping him in his desperate object untried; so I resolved to go round to the front of the convent again, and ring at the gate-bell at all hazards.
By the merest chance I looked up as I passed the side of the outhouse where the jagged hole was, and noticed that it was pierced rather high in the wall.
As I stopped to observe this, the closeness of the atmosphere in the wood seemed to be affecting me more unpleasantly than ever.
I waited a minute and untied my cravat.
Closeness?
surely it was something more than that.

The air was even more distasteful to my nostrils than to my lungs.

There was some faint, indescribable smell loading it--some smell of which I had never had any previous experience--some smell which I thought (now that my attention was directed to it) grew more and more certainly traceable to its source the nearer I advanced to the outhouse.
By the time I had tried the experiment two or three times, and had made myself sure of this fact, my curiosity became excited.

There were plenty of fragments of stone and brick lying about me.