reverberated harshly through the empty house. Holmes crouched back
against the wall, and I did the same, my hand closing upon the handle
of my revolver. Peering through the gloom, I saw the vague outline of a
man, a shade blacker than the blackness of the open door. He stood for
an instant, and then he crept forward, crouching, menacing, into the
room. He was within three yards of us, this sinister figure, and I had
braced myself to meet his spring, before I realized that he had no idea
of our presence. He passed close beside us, stole over to the window,
and very softly and noiselessly raised it for half a foot. As he sank to
the level of this opening, the light of the street, no longer dimmed by
the dusty glass, fell full upon his face. The man seemed to be beside
himself with excitement. His two eyes shone like stars, and his
features were working convulsively. He was an elderly man, with a thin,
projecting nose, a high, bald forehead, and a huge grizzled moustache.
An opera hat was pushed to the back of his head, and an evening dress
shirt-front gleamed out through his open overcoat. His face was gaunt
and swarthy, scored with deep, savage lines. In his hand he carried what
appeared to be a stick, but as he laid it down upon the floor it gave
a metallic clang. Then from the pocket of his overcoat he drew a bulky
object, and he busied himself in some task which ended with a loud,
sharp click, as if a spring or bolt had fallen into its place. Still
kneeling upon the floor he bent forward and threw all his weight and
strength upon some lever, with the result that there came a long,
whirling, grinding noise, ending once more in a powerful click. He
straightened himself then, and I saw that what he held in his hand was
a sort of gun, with a curiously misshapen butt. He opened it at the
breech, put something in, and snapped the breech-lock. Then, crouching
down, he rested the end of the barrel upon the ledge of the open window,
and I saw his long moustache droop over the stock and his eye gleam as
it peered along the sights. I heard a little sigh of satisfaction as