The river police seemed to be floating, suspended in the fog, which now was so dense that the water beneath was invisible. Inspector Rogers, who was in charge, fastened up his coat collar about his neck and turned to Stringer, the Scotland Yard man, who sat beside him in the stern of the cutter gloomily silent.  
“Time's wearing on,” said Rogers, and his voice was muffled by the fog as though he were speaking from inside a box. “There must be some hitch.”
 
“Work it out for yourself,” said the C. I. D. man gruffly. “We know that the office in Globe Road belongs to Gianapolis, and according to the Eastern Exchange he was constantly ringing up East 39951; that's the warehouse of Kan-Suh Concessions. He garages his car next door to the said warehouse, and to-night our scouts follow Gianapolis and Max from Piccadilly Circus to Waterloo Station, where they discharge the taxi and pick up Gianapolis' limousine. Still followed, they drive—where? Straight to the garage at the back of that wharf yonder! Neither Gianapolis, Max, nor the chauffeur come out of the garage. I said, and I still say, that we should have broken in at once, but Dunbar was always pigheaded, and he thinks Max is a tin god.”...
 
“Well, there's no sign from Max,” said Rogers; “and as we aren't ten yards above the wharf, we cannot fail to hear the signal. For my part I never noticed anything suspicious, and never had anything reported, about this ginger firm, and where the swell dope-shop I've heard about can be situated, beats me. It can't very well be UNDER the place, or it would be below the level of the blessed river!”
 
“This waiting makes me sick!” growled Stringer. “If I understand aright—and I'm not sure that I do—there are two women tucked away there somewhere in that place”—he jerked his thumb aimlessly into the fog; “and here we are hanging about with enough men in yards, in doorways, behind walls, and freezing on the river, to raid the Houses of Parliament!”
 
“It's a pity we didn't get the word from the hospitals before Max was actually inside,” said Rogers. “For three wealthy ladies to be driven to three public hospitals in a sort of semi-conscious condition, with symptoms of opium, on the same evening isn't natural. It points to the fact that the boss of the den has UNLOADED! He's been thoughtful where his lady clients were concerned, but probably the men have simply been kicked out and left to shift for themselves. If we only knew one of them it might be confirmed.”
 
“It's not worth worrying about, now,” growled Stringer. “Let's have a look at the time.”
 
He fumbled inside his overcoat and tugged out his watch.
 
“Here's a light,” said Rogers, and shone the ray of an electric torch upon the watch-face.
 
“A quarter-to-three,” grumbled Stringer. “There may be murder going on, and here we are.”...
 
A sudden clamor arose upon the shore, near by; a sound as of sledge-hammers at work. But above this pierced shrilly the call of a police whistle.
 
“What's that?” snapped Rogers, leaping up. “Stand by there!”
 
The sound of the whistle grew near and nearer; then came a voice—that of Sergeant Sowerby—hailing them through the fog.
 
“DUNBAR'S IN! But the gang have escaped! They've got to a motor launch twenty yards down, on the end of the creek”...
 
But already the police boat was away.
 
“Let her go!” shouted Rogers—“close inshore! Keep a sharp lookout for a cutter, boys!”
 
Stringer, aroused now to excitement, went blundering forward through the fog, joining the men in the bows. Four pairs of eyes were peering through the mist, the damnable, yellow mist that veiled all things.
 
“Curse the fog!” said Stringer; “it's just our damn luck!”
 
“Cutter 'hoy!” bawled a man at his side suddenly, one of the river police more used to the mists of the Thames. “Cutter on the port bow, sir!”
 
“Keep her in sight,” shouted Rogers from the stern; “don't lose her for your lives!”
 
Stringer, at imminent peril of precipitating himself into the water, was craning out over the bows and staring until his eyes smarted.
 
“Don't you see her?” said one of the men on the lookout. “She carries no lights, of course, but you can just make out the streak of her wake.”
 
Harder, harder stared Stringer, and now a faint, lighter smudge in the blackness, ahead and below, proclaimed itself the wake of some rapidly traveling craft.
 
“I can hear her motor!” said another voice.
 
Stringer began, now, also to listen.
 
Muffled sirens were hooting dismally all about Limehouse Reach, and he knew that this random dash through the night was fraught with extreme danger, since this was a narrow and congested part of the great highway. But, listen as he might, he could not detect the sounds referred to.
 
The brazen roar of a big steamer's siren rose up before them. Rogers turned the head of the cutter sharply to starboard but did not slacken speed. The continuous roar grew deeper, grew louder.
 
“Sharp lookout there!” cried the inspector from the stern.
 
Suddenly over their bows uprose a black mass.
 
“My God!” cried Stringer, and fell back with upraised arms as if hoping to fend off that giant menace.
 
He lurched, as the cutter was again diverted sharply from its course, and must have fallen under the very bows of the oncoming liner, had not one of the lookouts caught him by the collar and jerked him sharply back into the boat.
 
A blaze of light burst out over them, and there were conflicting voices raised one in opposition to another. Above them all, even above the beating of the twin screws and the churning of the inky water, arose that of an officer from the bridge of the steamer.
 
“Where the flaming hell are YOU going?” inquired this stentorian voice; “haven't you got any blasted eyes and ears”...
 
High on the wash of the liner rode the police boat; down she plunged again, and began to roll perilously; up again—swimming it seemed upon frothing milk.
 
The clangor of bells, of voices, and of churning screws died, remote, astern.
 
“Damn close shave!” cried Rogers. “It must be clear ahead; they've just run into it.”
 
One of the men on the lookout in the bows, who had never departed from his duty for an instant throughout this frightful commotion, now reported:
 
“Cutter crossing our bow, sir! Getting back to her course.”
 
“Keep her in view,” roared Rogers.
 
“Port, sir!”
 
“How's that?”
 
“Starboard, easy!”
 
“Keep her in view!”
 
“As she is, sir!”
 
Again they settled down to the pursuit, and it began to dawn upon Stringer's mind that the boat ahead must be engined identically with that of the police; for whilst they certainly gained nothing upon her, neither did they lose.
 
“Try a hail,” cried Rogers from the stern. “We may be chasing the wrong boat!”
 
“Cutter 'hoy!” bellowed the man beside Stringer, using his hands in lieu of a megaphone—“heave to!”
 
“Give 'em 'in the King's name!'” directed Rogers again.
 
“Cutter 'hoy,” roared the man through his trumpeted hands,—“heave to—in the King's name!”
 
Stringer glared through the fog, clutching at the shoulder of the shouter almost convulsively.
 
“Take no notice, sir,” reported the man.
 
“Then it's the gang!” cried Rogers from the stern; “and we haven't made a mistake. Where the blazes are we?”
 
“Well on the way to Blackwall Reach, sir,” answered someone. “Fog lifting ahead.”
 
“It's the rain that's doing it,” said the man beside Stringer.
 
Even as he spoke, a drop of rain fell upon the back of Stringer's hand. This was the prelude; then, with ever-increasing force, down came the rain in torrents, smearing out the fog from the atmosphere, as a painter, with a sponge, might wipe a color from his canvas. Long tails of yellow vapor, twining—twining—but always coiling downward, floated like snakes about them; and the oily waters of the Thames became pock-marked in the growing light.
 
Stringer now quite clearly discerned the quarry—a very rakish-looking motor cutter, painted black, and speeding seaward ahead of them. He quivered with excitement.
 
“Do you know the boat?” cried Rogers, addressing his crew in general............