“Been havin’ a pipe, Sin?” he asked, winking at his companion.  “I can smell something like opium!”

“No smokee opium,” murmured Sin Sin Wa complacently.  “Smokee Woodbine.”

“Ho, ho!” laughed the other constable.  “I don’t think.”

“You likee tly one piecee pipee one time?” inquired the Chinaman.  “Gotchee fliend makee smokee.”

The man who had poked the fire slapped his companion on the back.

“Now’s your chance, Jim!” he cried.  “You always said you’d like to have a cut at it.”

“H’m!” muttered the other.  “A ‘double’ o’ that fifteen over-proof Jamaica of yours, Sin, would hit me in a tender spot tonight.”

“Lum?” murmured Sin Sin blandly.  “No hate got.”

He resumed his seat on the tea-chest, and the raven muttered sleepily, “Sin Sin—­Sin.”

“H’m!” repeated the constable.

He raised the skirt of his heavy top-coat, and from his trouser-pocket drew out a leather purse.  The eye of Sin Sin Wa remained fixed upon a distant corner of the room.  From the purse the constable took a shilling, ringing it loudly upon the table.

“Double rum, miss, please!” he said, facetiously.  “There’s no treason allowed nowadays, so my pal’s—­”

“I stood yours last night Jim, anyway!” cried the other, grinning.  “Go on, stump up!”

Jim rang a second shilling on the table.

“Two double rums!” he called.

Sin Sin Wa reached a long arm into the little cupboard beside him and withdrew a bottle and a glass.  Leaning forward he placed bottle and glass on the table, and adroitly swept the coins into his yellow palm.

“Number one p’lice chop,” croaked the raven.

“You’re right, old bird!” said Jim, pouring out a stiff peg of the spirit and disposing of it at a draught.  “We should freeze to death on this blasted riverside beat if it wasn’t for Sin Sin.”

He measured out a second portion for his companion, and the latter drank the raw spirit off as though it had been ale, replaced the glass on the table, and having adjusted his belt and lantern in that characteristic way which belongs exclusively to members of the Metropolitan Police Force, turned and departed.

“Good night, Sin,” he said, opening the door.

“So-long,” murmured the Chinaman.

“Good night, old bird,” cried Jim, following his colleague.

“So-long.”

The door closed, and Sin Sin Wa, shuffling across, rebolted it.  As Sir Lucien came out from his hiding-place Sin Sin Wa returned to his seat on the tea-chest, first putting the glass, unwashed, and the rum bottle back in the cupboard.