e write a letter now, rather than six years ago? Again, the
letter speaks of giving her justice. What justice can she have? It is
too much to suppose that her father is still alive. There is no other
injustice in her case that you know of."

"There are difficulties; there are certainly difficulties," said
Sherlock Holmes, pensively. "But our expedition of to-night will solve
them all. Ah, here is a four-wheeler, and Miss Morstan is inside. Are
you all ready? Then we had better go down, for it is a little past the
hour."

I picked up my hat and my heaviest stick, but I observed that Holmes
took his revolver from his drawer and slipped it into his pocket. It
was clear that he thought that our night's work might be a serious one.

Miss Morstan was muffled in a dark cloak, and her sensitive face was
composed, but pale. She must have been more than woman if she did not
feel some uneasiness at the strange enterprise upon which we were
embarking, yet her self-control was perfect, and she readily answered
the few additional questions which Sherlock Holmes put to her.

"Major Sholto was a very particular friend of papa's," she said. "His
letters were full of allusions to the major. He and papa were in
command of the troops at the Andaman Islands, so they were thrown a
great deal together. By the way, a curious paper was found in papa's
desk which no one could understand. I don't suppose that it is of the
slightest importance, but I thought you might care to see it, so I
brought it with me. It is here."

Holmes unfolded the paper carefully and smoothed it out upon his knee.
He then very methodically examined it all over with his double lens.

"It is paper of native Indian manufacture," he remarked. "It has at
some time been pinned to a board. The diagram upon it appears to be a
plan of part of a large building with numerous halls, corridors, and
passages. At one point is a small cross done in red ink, and above it
is '3.37 from left,' in faded pencil-writing. In the left-hand corner
is a curious hieroglyphic like four crosses in a line with their arms
touching. Beside it is written, in very rough and coarse characters,
'The sign of the four,--Jonathan Small, Mahomet Singh, Abdullah Khan,
Dost Akbar.' No, I confess that I do not see how this bears upon the
matter. Yet it is evidently a document of importance. It has been kept
carefully in a pocket-book; for the one side is as clean as the other."

"It was