as actually reading my thoughts in
the dark. "Instead of putting me on the scent, it may console you to
know, Mr. Betteredge (with your interest in Rosanna), that you have been
the means of throwing me off. What the girl has done, to-night, is clear
enough, of course. She has joined the two chains, and has fastened them
to the hasp in the tin case. She has sunk the case, in the water or
in the quicksand. She has made the loose end of the chain fast to some
place under the rocks, known only to herself. And she will leave the
case secure at its anchorage till the present proceedings have come
to an end; after which she can privately pull it up again out of its
hiding-place, at her own leisure and convenience. All perfectly plain,
so far. But," says the Sergeant, with the first tone of impatience in
his voice that I had heard yet, "the mystery is--what the devil has she
hidden in the tin case?"

I thought to myself, "The Moonstone!" But I only said to Sergeant Cuff,
"Can't you guess?"

"It's not the Diamond," says the Sergeant. "The whole experience of my
life is at fault, if Rosanna Spearman has got the Diamond."

On hearing those words, the infernal detective-fever began, I suppose,
to burn in me again. At any rate, I forgot myself in the interest of
guessing this new riddle. I said rashly, "The stained dress!"

Sergeant Cuff stopped short in the dark, and laid his hand on my arm.

"Is anything thrown into that quicksand of yours, ever thrown up on the
surface again?" he asked.

"Never," I answered. "Light or heavy whatever goes into the Shivering
Sand is sucked down, and seen no more."

"Does Rosanna Spearman know that?"

"She knows it as well as I do."

"Then," says the Sergeant, "what on earth has she got to do but to tie
up a bit of stone in the stained dress and throw it into the quicksand?
There isn't the shadow of a reason why she should have hidden it--and
yet she must have hidden it. Query," says the Sergeant, walking on
again, "is the paint-stained dress a petticoat or a night-gown? or is it
something else which there is a reason for preserving at any risk? Mr.
Betteredge, if nothing occurs to prevent it, I must go to Frizinghall
to-morrow, and discover what she bought in the town, when she privately
got the materials for making the substitute dress. It's a risk to
leave the house, as things are now--but it's a worse risk still to stir
another step in this matter in the dark. Excuse my being a little