Douglas Preston - Riptide

St. John turned back to the parchment. "Extraordinary," he murmured. "Some of these even escaped our researchers at the Archivos de los Indios in Seville."

"My Spanish is a little rusty, so I wasn't able to translate everything. But this was the thing I found most interesting." Hatch pointed to a folder marked Archivos de la. Ciudad de Cadiz. Inside was a dark, blurry photograph of an original manuscript, much soiled by handling.

"Let's see," St. John began. "Records from the Court of Cadiz, 1661 to 1700. Octavo 16. Hmm. Throughout the reign of the Holy Roman Emperor Carolus II —in other words Charles II— we were sorely troubled by pirates. In 1690 alone, the Royal Plate Fleet —or the silver fleet, although the Flota de Plata also carried a great deal of gold ..."

"Go on."

"... Was seized and plundered by the heathen pirate, Edward Ockham, at a cost to the crown of ninety million reales. He became our greatest plague, a pestilence sent by the very devil himself. At length, upon much debate, privy counselors allowed us to wield St. Michael's Sword, our greatest, most secret, and most terrible treasure. In nomine patre, may God have mercy on our souls for doing so."

St. John put the folder down, his brow furrowed in interest. "What does this mean, our greatest, most secret, and most terrible treasure?"

"No idea. Maybe they thought the sword had magical properties. That it would scare away Ockham. Some kind of Spanish Excalibur."

"Unlikely. The world was poised at the Age of Enlightenment, remember, and Spain was one of the most civilized countries in Europe. Surely the emperor's privy counselors would not have believed a medieval superstition, let alone hung a matter of state on it."

"Unless the sword was truly cursed," Hatch murmured facetiously, widening his eyes dramatically.

St. John did not smile. "Have you shown these to Captain Neidelman yet?"

"No. Actually, I was thinking of e-mailing the transcriptions to an old friend who lives in Cadiz. Marquesa Hermione Concha de Hohenzollern."

"Marquesa?" St. John asked.

Hatch smiled. "You wouldn't know it to look at her. But she loves to bore you with her long and distinguished pedigree. I met her when I was involved with Medecins sans Frontieres. She's very eccentric, almost eighty but a top-notch researcher, reads every European language and many dialects and archaic forms."

"Perhaps you're right to look outside for assistance," St. John said. "The Captain's so involved with the Water Pit I doubt he'd spare the time to look at this. You know, he came to me yesterday after the insurance adjuster left, asking me to compare the depth and width of the Pit to various cathedral spires. Then he wanted to sketch out more bracing that could act as the internal support system of a cathedral, re-creating the stresses and loads of Macallan's original spire. Essentially, defuse the Pit."

"So I understand. Sounds like a hell of a job."

"The actual construction won't be very involved," St. John said. "It was the background research that was so complex." He spread his hands at the flurry of books. "It took me the rest of the day and all night just to sketch things out."

"You'd better rack out for a while, then. I'm headed down to Stores to pick up Macallan's second journal. Thanks for your help with the translation." Hatch gathered the folders and turned to go.

"Just a moment!" St. John said.

As Hatch looked back, the Englishman stood up and came around the desk. "I mentioned I'd made a discovery."

"That's right, you did."

"It has to do with Macallan." St. John played with his tie knot self-consciously. "Well, indirectly with Macallan. Take a look at this." He took a sheet of paper from his desk and held it out. Hatch examined the single line of letters it contained:

ETAONISRHLDCUFPMWYBGKQXYZ

"Looks like gibberish," Hatch said.

"Look more closely at the first seven letters."

Hatch spelled them out loud. "E, T, A, O ... hey, wait a minute. Eta Onis! That's who Macallan dedicated his book on architecture to." He paused, looking at the sheet.

"It's the frequency table of the English language," St. John explained. "The order that letters are most likely to be used in sentences. Cryptanalysts use it to decrypt coded messages."

Hatch whistled. "When did you notice this?"

St. John grew even more self-conscious. "The day after Kerry died, actually. I didn't say anything about it to anyone. I felt so stupid. To think it had been staring me in the face all this time. But the more I thought about it, the more it seemed to explain. I realized Macallan had been much more than just an architect. If he knew about the frequency table, it means he was probably involved with London's intelligence community, or at the very least some secret society. So I did some wider background checking. And I stumbled across some bits of information too intriguing to be coincidental. I'm now sure that, during those missing years of Macallan's life, he worked for the Black Chamber."

"The what?"

"It's fascinating, really. You see—" St. John stopped suddenly and looked over his shoulder. Hatch realized, with a sympathetic pang, that St. John had been looking in the direction of Wopner's room, anticipating a caustic remark about what the dusty old antiquarian found fascinating.

"Come on," Hatch said. "You can explain as I walk down to Stores."

"The Black Chamber," St. John continued as they stepped out into the morning mist, "was a secret department of the English post office. Their duty was to intercept sealed communications, transcribe the contents, then reseal them with forged seals. If the transcribed documents were in code, they were sent to something called the deciphering branch. The plaintext was eventually sent on to the king or certain high ministers, depending on the communication."

"That much cloak-and-dagger stuff went on in Stuart England?"

"It wasn't just England. All European countries had similar setups. It was actually a popular place for highly intelligent, well-placed young aristocrats to work. If they made good cryptanalysts, they were rewarded with high pay and positions at court."

Hatch shook his head. "I had no idea."

"Not only that. Reading between the lines of some of the old court records, I believe Macallan was most likely a double agent, working for Spain because of his Irish sympathies. But he was found out. I think the real reason he left the country was to save his life. Perhaps he was being sent to America not only to construct a cathedral for New Spain, but for other, clandestine, reasons."

"And Ockham put a stop to those plans."

"Yes. But in Macallan, he got much more than he ever bargained for."

Hatch nodded. "That would explain why Macallan was so adept at using codes and secret inks in his journal."

"And why his second code was so devilish. Not many people would have the presence of mind to plan a double cross as elaborate as the Water Pit." St. John fell silent a moment. "I mentioned this to Neidelman when we spoke yesterday afternoon."

"And?"

"He told me it was interesting, and that we should look into it at some point, but that the priority was stabilizing the Pit and retrieving the gold." A pale smile moved quickly across his features. "That's why there's little reason to show him those documents you uncovered. He's simply too involved with the dig to think of anything that isn't directly related."

They arrived at the storage shed. Since the initial finds at the pirate encampment, the shed had been beefed up from its original ramshackle appearance. Now, bars had been placed at the two small windows, and a Thalassa guard sat inside the entrance, logging everything that went in and out.