ful to me, Petrie," he replied; "as a counsel for
the defense you constantly rectify my errors of prejudice. Yet I am
convinced that our presence at Slattin's house last night prevented
Fu-Manchu from finishing off this little matter as he had designed to
do."

"What has given you this idea?"

"Weymouth is responsible. He has rung me up from the Yard. The constable
on duty at the house where the murder was committed, reports that some
one, less than an hour ago, attempted to break in."

"Break in!"

"Ah! you are interested? I thought the circumstance illuminating, also!"

"Did the officer see this person?"

"No; he only heard him. It was some one who endeavored to enter by the
bathroom window, which, I am told, may be reached fairly easily by an
agile climber."

"The attempt did not succeed?"

"No; the constable interrupted, but failed to make a capture or even to
secure a glimpse of the man."

We were both silent for some moments; then:

"What do you propose to do?" I asked.

"We must not let Fu-Manchu's servants know," replied Smith, "but
to-night I shall conceal myself in Slattin's house and remain there
for a week or a day--it matters not how long--until that attempt is
repeated. Quite obviously, Petrie, we have overlooked something which
implicates the murderer with the murder! In short, either by accident,
by reason of our superior vigilance, or by the clumsiness of his plans,
Fu-Manchu for once in an otherwise blameless career, has left a clue!"

CHAPTER X. THE CLIMBER RETURNS

In utter darkness we groped our way through into the hallway of
Slattin's house, having entered, stealthily, from the rear; for Smith
had selected the study as a suitable base of operations. We reached it
without mishap, and presently I found myself seated in the very chair
which Karamaneh had occupied; my companion took up a post just within
the widely opened door.

So we commenced our ghostly business in the house of the murdered man--a
house from which, but a few hours since, his body had been removed. This
was such a vigil as I had endured once before, when, with Nayland Smith
and another, I had waited for the coming of one of Fu-Manchu's death
agents.

Of all the sounds which, one by one, now began to detach themselves
from the silence, there was a particular sound, homely enough at another
time, which spoke to me more dreadfully than the rest. It was the
ticking of the clock upon the mantelpiece; and I thought