Taking a firm hold of the roots of the seaweed with my left hand, I laid myself down over the brink, and felt with my right hand under the overhanging edges of the rock.  My right hand found the chain.

I drew it up without the slightest difficulty.  And there was the japanned tin case fastened to the end of it.

The action of the water had so rusted the chain, that it was impossible for me to unfasten it from the hasp which attached it to the case.  Putting the case between my knees and exerting my utmost strength, I contrived to draw off the cover.  Some white substance filled the whole interior when I looked in.  I put in my hand, and found it to be linen.

In drawing out the linen, I also drew out a letter crumpled up with it.  After looking at the direction, and discovering that it bore my name, I put the letter in my pocket, and completely removed the linen.  It came out in a thick roll, moulded, of course, to the shape of the case in which it had been so long confined, and perfectly preserved from any injury by the sea.

I carried the linen to the dry sand of the beach, and there unrolled and smoothed it out.  There was no mistaking it as an article of dress.  It was a nightgown.

The uppermost side, when I spread it out, presented to view innumerable folds and creases, and nothing more.  I tried the undermost side, next—­and instantly discovered the smear of the paint from the door of Rachel’s boudoir!

My eyes remained riveted on the stain, and my mind took me back at a leap from present to past.  The very words of Sergeant Cuff recurred to me, as if the man himself was at my side again, pointing to the unanswerable inference which he drew from the smear on the door.

“Find out whether there is any article of dress in this house with the stain of paint on it.  Find out who that dress belongs to.  Find out how the person can account for having been in the room, and smeared the paint between midnight and three in the morning.  If the person can’t satisfy you, you haven’t far to look for the hand that took the Diamond.”

One after another those words travelled over my memory, repeating themselves again and again with a wearisome, mechanical reiteration.  I was roused from what felt like a trance of many hours—­from what was really, no doubt, the pause of a few moments only—­by a voice calling to me.  I looked up, and saw that Betteredge’s patience had failed him at last.  He was just visible between the sandhills, returning to the beach.

The old man’s appearance recalled me, the moment I perceived it, to my sense of present things, and reminded me that the inquiry which I had pursued thus far still remained incomplete.  I had discovered the smear on the nightgown.  To whom did the nightgown belong?

My first impulse was to consult the letter in my pocket—­the letter which I had found in the case.

As I raised my hand to take it out, I remembered that there was a shorter way to discovery than this.  The nightgown itself would reveal the truth, for, in all probability, the nightgown was marked with its owner’s name.