wn! Oh! it was not so simple a
flight--as you would realize if you knew the place. The street, which
the window overlooked, was bounded by a blank wall, on the opposite
side, for thirty or forty yards along; and as we had been having heavy
rains, it was full of glutinous mud. Furthermore, the boy whom I had
left in charge had been sitting in the doorway immediately below the
office window watching for my return ever since his last visit to the
room above...."

"She must have bribed him," I said bitterly, "or corrupted him with
her infernal blandishments."

"I'll swear she did not," rapped Smith decisively. "I know my man, and
I'll swear she did not. There were no marks in the mud of the road to
show that a ladder had been placed there; moreover, nothing of the
kind could have been attempted whilst the boy was sitting in the
doorway; that was evident. In short, she did not descend into the
roadway and did not come out by the door...."

"Was there a gallery outside the window?"

"No; it was impossible to climb to right or left of the window or up
on to the roof. I convinced myself of that."

"But, my dear man!" I cried, "you are eliminating every natural mode
of egress! Nothing remains but flight."

"I am aware, Petrie, that nothing remains but flight; in other words,
I have never to this day understood how she quitted the room. I only
know that she did."

"And then?"

"I saw in this incredible escape the cunning hand of Dr.
Fu-Manchu--saw it at once. Peace was ended; and I set to work along
certain channels without delay. In this manner I got on the track at
last, and learnt, beyond the possibility of doubt, that the Chinese
doctor lived--nay! was actually on his way to Europe again!"

There followed a short silence. Then--

"I suppose it's a mystery that will be cleared up some day," concluded
Smith; "but to date the riddle remains intact." He glanced at the
clock. "I have an appointment with Weymouth; therefore, leaving you to
the task of solving this problem which thus far has defied my own
efforts, I will get along."

He read a query in my glance.

"Oh! I shall not be late," he added; "I think I may venture out alone
on this occasion without personal danger."

Nayland Smith went upstairs to dress, leaving me seated at my
writing-table deep in thought. My notes upon the renewed activity of
Dr. Fu-Manchu were stacked on my left hand, and, opening a new
writing-block, I commenced to add to them particu