At a point just above the sweep of Limehouse Reach a watchful river police patrol observed a moving speck of light on the right bank of the Thames. As if in answer to the signal there came a few moments later a second moving speck at a point not far above the district once notorious in its possession of Ratcliff Highway. A third light answered from the Surrey bank, and a fourth shone out yet higher up and on the opposite side of the Thames.  
The tide had just turned. As Chief Inspector Kerry had once observed, “there are no pleasure parties punting about that stretch,” and, consequently, when George Martin tumbled into his skiff on the Surrey shore and began lustily to pull up stream, he was observed almost immediately by the River Police.
 
Pulling hard against the stream, it took him a long time to reach his destination—stone stairs near the point from which the second light had been shown. Rain had ceased and the mist had cleared shortly after dusk, as often happens at this time of year, and because the night was comparatively clear the pursuing boats had to be handled with care.
 
George did not disembark at the stone steps, but after waiting there for some time he began to drop down on the tide, keeping close inshore.
 
“He knows we've spotted him,” said Sergeant Coombes, who was in one of the River Police boats. “It was at the stairs that he had to pick up his man.”
 
Certainly, the tactics of George suggested that he had recognized surveillance, and, his purpose abandoned, now sought to efface himself without delay. Taking advantage of every shadow, he resigned his boat to the gentle current. He had actually come to the entrance of Greenwich Reach when a dock light, shining out across the river, outlined the boat yellowly.
 
“He's got a passenger!” said Coombes amazedly.
 
Inspector White, who was in charge of the cutter, rested his arm on Coombes' shoulder and stared across the moving tide.
 
“I can see no one,” he replied. “You're over anxious, Detective-Sergeant—and I can understand it!”
 
Coombes smiled heroically.
 
“I may be over anxious, Inspector,” he replied, “but if I lost Sin Sin Wa, the River Police had never even heard of him till the C.I.D. put 'em wise.”
 
“H'm!” muttered the Inspector. “D'you suggest we board him?”
 
“No,” said Coombes, “let him land, but don't trouble to hide any more. Show him we're in pursuit.”
 
No longer drifting with the outgoing tide, George Martin had now boldly taken to the oars. The River Police boat close in his wake, he headed for the blunt promontory of the Isle of Dogs. The grim pursuit went on until:
 
“I bet I know where he's for,” said Coombes.
 
“So do I,” declared Inspector White; “Dougal's!”
 
Their anticipations were realized. To the wooden stairs which served as a water-gate for the establishment on the Isle of Dogs, George Martin ran in openly; the police boat followed, and:
 
“You were right!” cried the Inspector, “he has somebody with him!”
 
A furtive figure, bearing a burden upon its shoulder, moved up the slope and disappeared. A moment later the police were leaping ashore. George deserted his boat and went running heavily after his passenger.
 
“After them!” cried Coombes. “That's Sin Sin Wa!”
 
Around the mazey, rubbish-strewn paths the pursuit went hotly. In sight of Dougal's Coombes saw the swing door open and a silhouette—that of a man who carried a bag on his shoulder—pass in. George Martin followed, but the Scotland Yard man had his hand upon his shoulder.
 
“Police!” he said sharply. “Who's your friend?”
 
George turned, red and truculent, with clenched fists.
 
“Mind your own bloody business!” he roared.
 
“Mind yours, my lad!” retorted Coombes warningly. “You're no Thames waterman. Who's your friend?”
 
“Wotcher mean?” shouted George. “You're up the pole or canned you are!”
 
“Grab him!” said Coombes, and he kicked open the door and entered the saloon, followed by Inspector White and the boat's crew.
 
As they appeared, the Inspector conspicuous in his uniform, backed by the group of River Police, one of whom grasped George Martin by his coat collar:
 
“Splits!” bellowed Dougal in a voice like a fog-horn.
 
Twenty cups of tea, coffee and cocoa, too hot for speedy assimilation, were spilled upon the floor.
 
The place as usual was crowded, more particularly in the neighborhood of the two stoves. Here were dock laborers, seamen and riverside loafers, lascars, Chinese, Arabs, negroes and dagoes. Mrs. Dougal, defiant and red, brawny arms folded and her pose as that of one contemplating a physical contest, glared from behind the “solid” counter. Dougal rested his hairy hands upon the “wet” counter and revealed his defective teeth in a vicious snarl. Many of the patrons carried light baggage, since a P and O boat, an oriental, and the S. S. Mahratta, were sailing that night or in the early morning, and Dougal's was the favorite house of call for a doch-an-dorrich for sailormen, particularly for sailormen of color.
 
Upon the police group became focussed the glances of light eyes and dark eyes, round eyes, almond-shaped eyes, and oblique eyes. Silence fell.
 
“We are police officers,” called Coombes formally. “All papers, please.”
 
Thereupon, without disturbance, the inspection began, and among the papers scrutinized were those of one, Chung Chow, an able-bodied Chinese seaman. But since his papers were in order, and since he possessed two eyes and wore no pigtail, he excited no more interest in the mind of Detective-Sergeant Coombes than did any one of the other Chinamen in the place.
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