udin, one of the master wizards of modern times, quitted Petrograd
by two gates at the same hour according to credible witnesses; but
his performance sinks into insignificance beside that of a Chinese
predecessor who flourished under one of the Ming emperors. The palace
of this potentate was approached by gates, each having twelve locks, and
each being watched by twelve guards. Nevertheless a distinguished member
of the wizard family not only gained access to the imperial presence
but also departed again unseen by any of the guards, and leaving all the
gates locked behind him! If Detective-Sergeant Coombes had known this
story he might not have experienced such complete confidence.

That door of Sin Sin Wa's establishment which gave upon a little
backyard was oiled both lock and hinge so that it opened noiselessly.
Like a shadow, like a ghost, Sin Sin Wa crept forth, closing the door
behind him. He carried a sort of canvas kit-bag, so that one observing
him might have concluded that he was "moving."

Resting his bag against the end wall, he climbed up by means of holes in
the neglected brickwork until he could peer over the top. A faint smell
of tobacco smoke greeted him: a detective was standing in the lane
below. Soundlessly, Sin Sin Wa descended again. Raising his bag he
lifted it lovingly until it rested upright upon the top of the wall
and against the side of the house. The night was dark and still. Only
a confused beating sound on the Surrey bank rose above the murmur of
sleeping London.

From the rubbish amid which he stood, Sin Sin Wa selected a piece of
rusty barrel-hoop. Cautiously he mounted upon a wooden structure built
against the end wall and raised himself upright, surveying the prospect.
Then he hurled the fragment of iron far along the lane, so that it
bounded upon a strip of corrugated roofing in a yard twice removed from
his own, and fell clattering among a neighbor's rubbish.

A short exclamation came from the detective in the lane. He could be
heard walking swiftly away in the direction of the disturbance. And ere
he had gone six paces, Sin Sin Wa was bending like an inverted U over
the wall and was lowering his precious bag to the ground. Like a cat he
sprang across and dropped noiselessly beside it.

"Hello! Who's there?" cried the detective, standing by the wall of the
house which Sin Sin Wa had selected as a target.

Sin Sin Wa, bag in hand, trotted, soft of foot, across the lane and into