Read it through once

Knowing what I knew, I set up an inference of my own here. I believed the iron to be my convict’s iron,—the iron I had seen and heard him filing at, on the marshes,—but my mind did not accuse him of having put it to its latest use. For I believed one of two other persons to have become possessed of it, and to have turned it to this cruel account. Either Orlick, or the strange man who had shown me the file.