air of faint suspicion.

"Gentleman!" accosted the thin, curled lips in a tone that was
well-nigh personal.

"Buy nothing," Peter Moore said curtly.

"You see my--my see you," observed Ah Sih King, reverting, as he deemed
fitting, to pidgin.

The wireless operator turned his back impolitely; Ah Sih King did
likewise. When he turned again, sharply, the oily smile was gone, a
look of concern having crept into his sly, old face, and the slightly
bent shoulders of the much slier young man were several strides distant.

A faint hiss, as of warning, issued from the carmine lips of the
Chinese woman. Then the window closed noiselessly, and Chinatown,
having paid not the slightest heed to the incident, pattered about its
multifarious businesses, none the wiser.

There was an indefinable something in this incident which caused
creases to appear across Moore's brow. Why had two notes been thrown?
The puzzle sifted down to this possibility: Some one behind the Chinese
woman had thrown a ball of red paper, a note, into the street.

Then she had beckoned him to wait, had written a second note, perhaps
to warn him away. He glanced furtively at the second note, saw that it
was written in Chinese, and thereupon decided in return for many favors
to call upon Lo Ong for a translation.

Chinatown now was slowly vanishing from view, swallowed by the gray
blanket of fog which rolled in from the Pacific through the mouth of
the harbor. Retracing his steps through the mist, Moore descended the
narrow stone stairway and tapped on the oblong of iron with his heavy
seal ring. A shutter clinked, uneasy eyes scrutinized him, and he
heard the bolt slide back. He opened the door and entered, restoring
the bolt to its place.

The room was low, deep and dark under the flickering light of a single
dong, which hung from the ceiling at the end of a roped-up cluster of
fine brass chains. The rich, stupefying odor of opium tainted the
heavy air. The orange flame, motionless as if it were carved from
solid metal, showed the room to be bare except for a few grass mats
scattered about in the irregular round shadow under it.

To one of these mats Lo Ong, gaunt, curious, even hostile, retreated,
squatting with his delicately thin hands folded over his abdomen. A
look of recognition disturbed only for the instant the placidity of the
ochre features.

"No come buy?" he intoned, as if Peter Moore had never passed under
that piercing gaze b