Burton pushed himself back upright, turned, frowned, and said: “You're referring to his subsequent hallucinations?”

Swinburne nodded. “You said he ranted and raved about dragons dragging him away from something. Dragons, Richard-mythical reptiles, just like the Shayturay, the African Naga. Is that a coincidence, do you think?”

“And the Naga are associated with a fabled black diamond that fell from the sky and gave rise to the Nile,” Burton whispered. “Bloody hell, Algy, did he see the African stone?”

“It would certainly account for his subsequent actions.”

Burton whistled and ran his fingers through his hair. He paced over to the fireplace, took another cigar from the box on the mantelpiece, and immediately forgot it, holding it unlit while he gazed thoughtfully at Swinburne.

“When Babbage said the Technologists had become aware of the black diamonds, I wondered how. Now we know: Speke told Oliphant and Oliphant told the Technologists.”

“Yes, and that's when the whole game changed. Let me ask you a question: why did Speke receive Murchison's backing for a second expedition? He's an inept geographer, a terrible public speaker, a bad writer, and has proven himself thoroughly unreliable. Yet he was chosen over you. Why?”

Burton's jaw dropped. The cigar fell from his fingers.

“My God,” he whispered. “My God. At last it's making sense. The Rakes and Technologists must have offered to fund him!”

“What still remains unclear is what actually happened during that second expedition. He took with him a young soldier named James Augustus Grant-I don't know if he was a Technologist or a Rake, but one or the other, I should think-and they used swans to fly to Kazeh. Speke failed to properly guard the birds and lions killed them. That was the first of a string of disasters that forced him to return to Zanzibar. When he arrived there, Grant was no longer with him. Speke claimed that his colleague had died of fever and was buried near the shore of the lake.”

Burton dropped back into his armchair and said: “He also reaffirmed that he'd discovered the source of the Nile-but, again, his evidence was pathetically flawed.”

Swinburne grunted his agreement. “He was scheduled to give a fuller account at the Bath Assembly Rooms last year. Instead, knowing that you were going to expose the scale of his ineptitude, he shot himself in the head. Oliphant abducted him from the hospital, and the Technologists replaced the damaged half of his brain with a clockwork mechanism.”

“Babbage's prototype. I never understood why they did that until now. Bismillah! They still needed him to show them where the diamond was. But then the Spring Heeled Jack affair occurred, the Technologist and Rake alliance diverted their resources to capturing Edward Oxford, and Speke was left trailing about after them, awaiting further orders. When I defeated the alliance and killed Oliphant, he fled.”

Swinburne twitched, jerked, and jumped to his feet.

“Where do you suppose he is now?”

“Brunel says he's in Prussia.”

“Hmm,” Swinburne hummed. “I wonder why there? Could he have arranged the Brundleweed theft?”

“Are you suggesting he's making a play for the Eyes?”

“Yes, I think it quite likely. If Darwin and his cronies implanted that device in his head to somehow impel him to retrieve the African Eye, is it not possible that it might also have driven him to acquire the Cambodian diamonds? If Speke or the alliance researched the matter, they will know that there were three Eyes and that the Choir Stones are the fragments of one of them.”

“You're making a lot of sense, Algy. In which case, if the Tichbornes really do have the South American stone and Speke is aware of it, they'll be his next target.”

“Then let's stop chinwagging and get ourselves to Tichborne House!”

Swinburne leaped to his feet and ran to the door. Burton followed.

“Really, Algy, there's no need for you to come.”

They descended to the ground floor.

“There's every need! You know how trouble dogs your footsteps and you're obviously not at the peak of physical fitness. What better time to call on your faithful assistant for support? I say, speaking of dogs, where's that blasted basset hound of yours?”

“Fidget? I don't know. In the kitchen with Mrs. Angell, probably.”

“Well, he can jolly well stay there, the brute! What say you?”

“I have no objection, and I'm certain he doesn't either, what with the scraps of food my esteemed housekeeper throws into his welcoming maw.”

Swinburne screeched and clapped his hands together. “I mean about me coming to Tichborne House with you, you buffoon!”

Burton smiled, took his assistant's top hat from the stand, and pushed it down over the little poet's mop of red hair.

“Very well, Algy. In truth, I'll be glad of your help, though I must confess, I was looking forward to using the rotorchair. I like flying! It's a shame the contraptions are single-seaters. I suppose we'll have to resort to the train.”

“No we won't.” Swinburne grinned. “I have a much better idea.”

“Why, it's Captain Burton and Mr. Swinburne!” Miss Isabella Mayson exclaimed. “How lovely to see you again. Come in! Come in!”

Doffing their hats, the two men stepped into the SPARTA building.

“I've just made some soup. Will you join us?”

“Thank you, that would be most welcome,” said Burton. He and Swinburne followed her through to the kitchen. As they crossed the threshold, a heavenly aroma assailed their nostrils, and there came an exclamation: “Hallo, hallo! Welcome to the chamber of bloomin’ miracles, gents!”

It was the voice rather than the face they recognised, for the vagrant philosopher Herbert Spencer had blossomed into something that might almost be called respectable. Above all, he looked cleaner; his beard had been shaved off, his large side-whiskers were combed, and the thin border of curly hair around his bald head was now short and neat, rather than wild and straggly. He'd filled out, too, losing the hungry gauntness that had marked him when they'd last met.

“I swears to you,” he said, shaking their hands, “there's no woman what can cook like Miss Mayson in the whole blessed world!”

“Herbert!” Swinburne said. “You look a new man!”

“It's the grub! This young lady here is a blinkin’ marvel with the dogs an’ the birds, but I tells you, gents, in the kitchen she's somethin’ else entirely! I ain't never indulged in victuals like it.”

“Thank you, Herbert,” said Miss Mayson. “Would you set a couple more places around the table, please? Our two friends will join us for lunch.”

Moments later, the king's agent and his assistant were enjoying a thick vegetable soup served with freshly baked bread.

“This is utterly delicious!” Burton declared.

“ Utterly utterly!” Swinburne added.

“Told you so!” said Spencer. “There ain't nothin’ so nourishing!”

“And you're obviously flourishing!” Swinburne rhymed.

“On which note, have you been ill?” Miss Mayson asked of Burton. “You look a little jaundiced.”

“I have been, yes. I suffer occasional bouts of malaria. The attacks are decreasing in frequency since my return from Africa but this latest was a bad one. Flying your swan through a rainstorm didn't help.”

“That were a nasty night, Boss,” Spencer observed. “I came down with the sniffles meself.”

“As a matter of fact, Miss Mayson-”

“Isabella, please!”

“Isabella. Swans are the reason for us dropping by. I was hoping we could hire a couple.”

“The last time you borrowed my swans, two were killed and one never came back,” the young woman noted, with a wry smile.

Burton nodded in acknowledgement. “I trust Scotland Yard compensated you?”

“Very generously, as a matter of fact.”

Spencer waved his spoon and announced: “That young Constable Bhatti has been here nearly every blinkin’ day, the scallywag!”