“Pepperwick?” one of the policemen said. “I know him. Who are you? What’s going on? Who’s shooting?”

“I’m Burton. Sir Richard Francis Burton. Keep these people back, Constable—?”

“Sergeant, sir. Piper.”

“Detective Inspector Trounce is on the wharf, Piper. He’s leading an assault against a group of men who’re intent on bombing the ceremony in Green Park.”

“The devil you say! A bomb?”

“Can you spare one of your fellows? We’re out to nab their leader.”

“I’ll come myself.” Piper turned to the other policemen and barked, “Tamworth, you’re with me. Lampwick, Carlyle, Patterson, you keep this crowd back, is that understood?”

He received a saluted response.

“Lead on,” he said to Burton.

Following the road, they skirted the front of the factory to the corner of Vauxhall Bridge. Here a set of concrete steps led down to the riverside and the outlet of the Effra. They found another gun battle raging there—Krishnamurthy and Bhatti, crouched behind a bulwark, were exchanging shots with men in the building.

Burton, Swinburne, and the policemen stayed low and ran to the two Indians.

Bhatti, bleeding profusely from a furrow on the side of his head, said, “Hello, fellows! They’re stubborn blighters! How many men do you have? Enough to rush the place?”

“They have double our number,” Burton answered. “But if we hold them in there, their plan is scuppered. Have you seen Crowley?”

“No sign of the hound. Is he with them?”

Burton frowned and turned to Swinburne. “You’re right, Algy. Something is badly amiss.”

He flinched as a bullet whined past his ear. Krishnamurthy returned fire before muttering, “I’m low on ammunition.”

Sergeant Piper addressed Constable Tamworth. “I’ll not tolerate a blessed shooting match on my beat. Run to the station, lad, and round up everyone you can. We’ll get into that building, forlorn hope or no.”

Tamworth took to his heels. Bullets drilled into the ground behind him.

“Modus operandi,” Swinburne murmured.

Burton looked at him. “Pardon?”

“Modus operandi. Crowley’s every move, right from the start—the murder of your friend Stroyan—has been undertaken in the context of your existence.”

“He said he was scared of me.”

“Yet he steadfastly refuses to kill you. Why?”

“I don’t know.”

“Because by disposing of you, he’d rid himself of the cause of his fear but not of the emotion itself. It isn’t enough for him. Fear has such a power. He wants to conquer it. Take control of it. Turn it into a strength. That is why you must live. That is why he must have you at his feet. Only then can the Supreme Man feel truly supreme.”

Burton recalled Doctor Monroe’s theory concerning Oliphant’s obsession with rats.

“Crowley is blinkered,” Swinburne went on. “He can only think to counter his greatest fear with your greatest fear.”

“By God!” Burton whispered. “He’s still underground.”

“Yes.”

Krishnamurthy shook his head. “We walked the complete length of the tunnel, Mr. Swinburne. There was no sign of the bomb or of Crowley. Wherever he is, he’s not by the Effra.”

“There are other tunnels.”

What had been lurking at the back of Burton’s mind suddenly blossomed into comprehension. He punched his palm, shouted, “Bismillah!” then looked at Sergeant Piper, and—acting on impulse—pointed at the whistle hanging around the policeman’s neck and barked, “Give me that!”

“What?” the policeman asked, puzzled.

“Your whistle, man! Now!”

Piper pulled the chain over his head and handed it to the explorer.

Burton took Swinburne by the arm and drew him toward the road, shouting back to the others, “Stay put! Keep them immobilised!”

“What are you doing?” Bhatti shouted after him.

“Saving the bloody Empire!” Burton yelled. “If it’s not too late!”

“Frater Perdurabo.”

(I shall endure to the end.)

—ALEISTER CROWLEY

Burton was enclosed twice over—first by the heavy undersea suit, and second by the claustrophobic sewer tunnel. Despite the mephitic reek rising from the thick, fast-flowing sludge in which he was immersed up to his knees and which threatened to suck him down at any moment, he’d left the faceplate of his helmet open.

His jaw was clamped shut, his eyes moved anxiously, and his chest was rising and falling with short, sharp breaths. He waded ahead, dragging behind him the long, weighty chain attached to the suit’s harness. With every step, his fear increased. He wrapped his gloved right hand around his swordstick—secured against him by one of the harness’s straps—and pulled at the chain with his left.

The light from the small lamps on either side of his headgear projected forward, illuminating about twenty feet of the tunnel, but beyond the radiance the brickwork plunged into absolute darkness. Burton couldn’t throw off the sensation that he was slipping down the throat of a gigantic beast.

One foot in front of the other. Keep your balance. Don’t think about how this has to end.

The Enochian gunmen had been a subterfuge, a diversion. Crowley never intended to take the Sagittarius. When Burton realised this—thanks to Swinburne’s insight—he’d raced back to Battersea Power Station, where Montague Penniforth was waiting and wondering where everyone had gone.

Rushing into Brunel’s office, the explorer consulted Bazalgette’s maps of subterranean London and discovered that, a few yards north of the Effra’s outlet, under Vauxhall Bridge, a small maintenance tunnel spanned the bed of the Thames. It gave access to the big west-to-east intercepting sewer, which ran parallel to the north bank of the river. Crowley need only have wheeled the bomb through it, turned left into the sewer system’s artery, and half a mile along its length he’d have come to what used to be the mouth of the Tyburn. That subterranean waterway, now enclosed by Bazalgette’s incredible brickwork and reduced to a trickle by a massive sluice gate, ran southward all the way from Hampstead.

It passed directly beneath Green Park.

There was no time for planning. The politicians and royal families were already gathering around the Victoria Memorial. No time, even, to speak with Abdu El Yezdi, who was, according to Nurse Nightingale, taking his final breaths.

Burton adopted the first scheme that came to mind—it had occurred to him in an instant while he was still with Krishnamurthy, Bhatti, and Piper—and after hastily grabbing the required equipment, he, Swinburne, and Penniforth boarded one of the DOGS’ small rotorships and sped northward. There was a wide exclusion zone around the park—no flying machines permitted except the Orpheus—and they possessed no means with which to signal Captain Lawless, so they’d angled to the west, flying in a wide arc over Belgravia and Hyde Park before landing in Berkeley Square. Here, after roughly pushing protesting pedestrians out of the way, they’d lifted an iron manhole cover, revealing the rungs of a ladder. Burton, donning the undersea suit, had issued instructions then descended into the darkness of the Tyburn tunnel, where he found himself in front of the giant sluice gate. It was impeding the swollen waters and accumulated sewage from a wide swathe of northern London, but was very slightly raised, and viscous filth was spurting from its base with tremendous force. The thick liquid would have knocked the explorer flying had he not been tethered by the chain to the windlass they’d picked up from the Royal Navy Air Service Station. Penniforth was attending to the apparatus, above ground, slowly unwinding it to allow Burton’s passage through the tunnel.

He’d walked half a mile—barely any distance at all—but it was the exact length of the chain and felt like ten times as far to Burton, who was increasingly exhausted by the weight of the links as they accumulated behind him.