Sowerby stared hard, and Stringer scratched his chin, reflectively.

“The same reasoning applies to the Gillingham Street people,” continued Dunbar.  “We haven’t the slightest idea of their whereabouts because we don’t even know who they were; but we do know something about Soames, and we’re looking for him, not because we think he did the murder, but because we think he can tell us who did.”

“Which brings us back to the old point,” interrupted Stringer, softly beating his fist upon the table at every word; “why are we looking for Soames in the east-end?”

“Because,” replied Dunbar, “we’re working on the theory that Soames, though actually not accessory to the crime, was in the pay of those who were"...

“Well?”—­Stringer spoke the word eagerly, his eyes upon the inspector’s face.

“And those who were accessory,”—­continued Dunbar, “were servants of Mr. King.”

“Ah!” Stringer brought his fist down with a bang—­“Mr. King!  That’s where I am in the dark, and where Sowerby, here, is in the dark.”  He bent forward over the table.  “Who the devil is Mr. King?”

Dunbar twirled his whisky glass between his fingers.

“We don’t know,” he replied quietly, “but Soames does, in all probability; and that’s why we’re looking for Soames.”

“Is it why we’re looking in Limehouse?” persisted Stringer, the argumentative.

“It is,” snapped Dunbar.  “We have only got one Chinatown worthy of the name, in London, and that’s not ten minutes’ walk from here.”

“Chinatown—­yes,” said Sowerby, his red face glistening with excitement; “but why look for Mr. King in Chinatown?”

“Because,” replied Dunbar, lowering his voice, “Mr. King in all probability is a Chinaman.”

“Who says so?” demanded Stringer.

“Max says so...”

“Max!”—­again Stringer beat his fist upon the table.  “Now we have got to it!  We’re working, then, not on our own theories, but on those of Max?”

Dunbar’s sallow face flushed slightly, and his eyes seemed to grow brighter.

“Mr. Gaston Max obtained information in Paris,” he said, “which he placed, unreservedly, at my disposal.  We went into the matter thoroughly, with the result that our conclusions were identical.  A certain Mr. King is at the bottom of this mystery, and, in all probability, Mr. King is a Chinaman.  Do I make myself clear?”

Sowerby and Stringer looked at one another, perplexedly.  Each man finished his drink in silence.  Then: 

“What took place in Paris?” began Sowerby.

There was an interruption.  A stooping figure in a shabby, black frock-coat, the figure of a man who wore a dilapidated bowler pressed down upon his ears, who had a greasy, Semitic countenance, with a scrubby, curling, sandy colored beard, sparse as the vegetation of a desert, appeared at Sowerby’s elbow.

He carried a brimming pewter pot.  This he set down upon a corner of the table, depositing himself in a convenient chair and pulling out a very dirty looking letter from an inside pocket.  He smoothed it carefully.  He peered, little-eyed, from the frowning face of Dunbar to the surprised countenance of Sowerby, and smiled with native amiability at the dangerous-looking Stringer.