“And what?” his other snapped.

“And he took one of the Sisters of Noble Benevolence.”

El Yezdi closed his eyes and clutched the sides of his chair. “Not—not Sadhvi Raghavendra?”

“Yes.”

“Damnation! Are you incapable of protecting anyone?”

“You,” Burton snarled, “are better placed to answer that question. How many have you allowed to die, old man?”

El Yezdi sucked in a breath and placed a fist over his heart. His lips drew back over his teeth.

“Stop it!” Nightingale commanded.

Burton held up his hands placatingly and took a step backward. “The point,” he said, “is that the presence alone of one of the Sisters accelerates healing. That, and the thefts of laboratory equipment and chemical supplies from locations all over the city, suggests that you’re right.”

Krishnamurthy said, “So he’s set up a laboratory of some sort? Where? In the Cauldron? That seems unlikely. The whole district is a cesspit of crime and grime.”

Burton noticed that Swinburne was becoming increasingly agitated, his limbs twitching and jerking spasmodically. He asked, “Algy?”

“Are you all blind?” the poet suddenly screeched, jumping into the air and swiping an arm at them. “My giddy aunt! Can’t you see it?”

Abdu El Yezdi chuckled. “How I’ve missed you, Algy! What revelation have you for us?”

“You!” Swinburne yelled, jabbing a finger at El Yezdi, “And you!” He pointed at Burton. “We’ve deduced what Crowley is here for, but you both appear to have forgotten what he did first, the moment he arrived. He came after you. He killed Isabel to hurt you. My hat! He even told you outright that he wants you at his feet. Why? Obviously because he considers you his biggest threat.”

The two Burtons looked at each other. The younger of them said, “So?”

“He didn’t kill you,” Swinburne said. “Surely, therefore, he hasn’t discounted your possible interference. Wherever he is, it must be somewhere he thinks you’d never go.”

“Which is where?” El Yezdi asked.

“Underground, of course! You hate it! You’re claustrophobic. Surely Sir Richard Francis Burton will forever be associated with wide-open spaces. Never with caves or vaults or tunnels! We’ve already seen Perdurabo hiding beneath Old Wardour Castle, and his people using the river under Saint Martin’s Lane. Doesn’t that give us an indication of his methods? And what better opportunity to make use of such than now, when Bazalgette is burrowing beneath the city and opening up ages-old subterranean thoroughfares?”

Brunel clanged, “But surely, if Crowley and his allies are using the sewer tunnels, the workers would have encountered them?”

Swinburne let loose a piercing shriek and danced around the desk, gesticulating wildly. “They have! The Norwood builders! The Norwood builders! Ghosts! The River Effra!”

“Hmm,” Daniel Gooch said. “It’s true, our workers have downed tools and are refusing to construct the tunnel any farther than Herne Hill.” He put a finger on the map. “The mouth of the Effra is a little east of Battersea, here, beside Vauxhall Bridge. The river runs beneath Kennington, Stockwell, and Brixton. That length of it has been enclosed in a brick tunnel, but beyond, up past Norwood to its source, the river is so far untouched.”

“And it flows right past Norwood Cemetery,” Swinburne declared, “which is famous for its extensive vaults and catacombs.”

“You think Crowley has set up a laboratory in them?” Bhatti asked.

El Yezdi slapped the side of his chair. “By Allah’s beard! I learned a long time ago to listen to Algy!” He waved a hand at Burton. “Go! Investigate!”

Burton glanced at the map. His face whitened. “Through five miles of tunnel?”

“Bhatti and I will take the tunnel, Sir Richard,” Krishnamurthy said. “You and Mr. Swinburne fly rotorchairs to the graveyard and enter the catacombs from above.”

Burton couldn’t hide his relief. El Yezdi snorted disdainfully. The explorer glowered at him then turned to Brunel. “Will you send someone to fetch Detective Inspector Trounce and Eliphas Levi? If we’re to hunt the nosferatu, I’d like those two with us.”

“I’ll send a rotorship to Scotland Yard at once.”

Brunel departed. Krishnamurthy crossed to a cabinet, opened it, and started to remove weapons from it.

Swinburne looked at El Yezdi. “The Swinburne you knew—was he like me?”

“Yes. A couple of years older.”

“What became of him?”

The old man thought for a moment then replied, “I’ve learned to consider time an organic thing, Algy. We are all entwined in it, we are all subject to it, and the choices we all make define its ever-developing patterns and rhythms. The Swinburne I knew came to understand its intricacies perhaps better than any other living person. I will not tell you his eventual fate—I don’t want to influence your behaviour—but I know he grew to be happy and content with his lot.”

“I don’t suppose I can ask for anything more than that,” Swinburne said, and declaimed, “For in the days we know not of did Fate begin weaving the web of days that wove your doom.”

“In the days we know not of?” El Yezdi exclaimed. “No, no. Fate is weaving today, Algy! Today!” He suddenly became quiet, and his eyes appeared to focus inward. “So be careful,” he muttered. “Don’t get tangled in the skein, as I did.” He turned to Nightingale. “Take me to my room, nurse.”

She wheeled him out.

Burton visibly relaxed.

“Difficult?” Swinburne asked.

“Sharing a room with my dying counterpart? Yes, Algy. Difficult.”

Bhatti and Krishnamurthy had armed themselves with a brace of pistols apiece. They passed revolvers to Burton and Swinburne. “It will take us a minimum of two hours to traverse the tunnel,” Krishnamurthy said. “Let’s say three, to be safe, as the upper reaches won’t be easy. We’ll leave immediately. Give us a head start. We should try to time it so we arrive in the catacombs simultaneously.”

Burton shook both men by the hand. “No rash actions,” he advised. “I want to get the measure of Crowley’s forces, nothing more. Keep your heads down. We’ll observe, evaluate, and return. Once we know exactly what we’re facing, we’ll plan our next move.”

The two Indians secured their weapons in their waistbands and left the room.

Burton and Swinburne waited with Daniel Gooch for Trounce and Levi’s arrival. After an hour had passed, they divined that Brunel’s men were having difficulty in locating the duo. Undoubtedly, the detective and occultist were caught up in the commotion in and around the East End.

“We’ll proceed without them,” Burton decided. “Bhatti and Krishnamurthy must be near halfway through the tunnel by now. Let’s go.”

Gooch led them through the station and out into the quadrangle where two rotorchairs had been prepared. They mounted the machines, pulled goggles over their eyes, and started the engines. Gooch gave them a thumbs-up as they rose on columns of steam and soared into the rain-filled air.

The cloud cover was thick, dark, and low. Remaining below it, they flew across the Royal Navy Air Service Station, past a network of railway tracks and rail yards, and out over the streets, homes, tanneries, and workhouses of Wandsworth. Angling southward, they passed over Clapham and Streatham. To his left, Burton saw Herne Hill. He guessed Bhatti and Krishnamurthy had reached and passed beneath it, and were by now following the river along the ages-old course it had cut through the area’s dense clay. The thought of it made him clench his teeth.

The rain suddenly intensified and lightning flashed. The clouds had taken on a curious formation, appearing to be twisting and circling around themselves.

A mile or so farther south, a wooded hill hove into view. Burton steered toward it, flew over it, and saw gravestones and mausoleums huddled amid the trees. He kept going, before landing in the yard of an inn a little to the south of the burial ground.