Read it through once

“I did as he ordered, and when the lawyer arrived I was asked to step up to the room. The fire was burning brightly, and in the grate there was a mass of black, fluffy ashes, as of burned paper, while the brass box stood open and empty beside it. As I glanced at the box I noticed, with a start, that upon the lid was printed the treble K which I had read in the morning upon the envelope.