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.
"Sorry about this," St. John said with a grimace as Hatch requisitioned Macallan's decrypted journal and showed Neidelman's note to the guard. "I'd be happy just to print you off a copy, but Streeter came by the other day and had all the cryptological material downloaded onto disks. All of it, including the log. Then everything was erased from the servers, and the backups wiped. If I knew more about computers, I might have—"
He was interrupted by a shout from the dim interior of the shed. A moment later Bonterre emerged, a clipboard in one hand and a curious circular object in the other. "My two favorite of men!" she said with a wide smile.
St. John, suddenly embarrassed, fell abruptly silent.
"How are things down at Pirateville?" Hatch asked.
"The work is almost done," Bonterre replied. "This morning we finish the last grid. But, as with lovemaking, the best comes at the end. Look at what one of my diggers unearthed yesterday." She held up the object in her hand, grin widening.
Hatch could see it was intricately worked, seemingly made of bronze, with numbers etched finely into the outer edge. Two pointed lengths of metal ran out from its center like the hands of a clock. "What is it?" he asked.
"An astrolabe. Used to determine latitude from the altitude of the sun. Worth ten times its weight in gold to any mariner in Red Ned's day. Yet it too was left behind." Bonterre ran her thumb caressingly along its surface. "The more I find, the more I am confused."
Suddenly, a loud cry sounded nearby.
"What was that?" St. John said, starting.
"Sounded like a howl of pain," Hatch said.
Bonterre pointed. "I think it came from the hut of the geologiste."
The three sprinted the short distance to Rankin's office. To Hatch's surprise, the blond bear of a man was not collapsed in agony, but was instead sitting in his chair, looking from a computer monitor to a lengthy printout, then back to the screen again.
"What's up?" Hatch cried.
Without looking at them, Rankin held out a palm, commanding silence. He checked the printout again, his lips moving as if counting something. Then he set it down. "Checks out both ways," he said. "Can't be a glitch this time."
"Has the man turned fou?" Bonterre asked.
Rankin turned toward them. "It's right," he said excitedly. "It's got to be. Neidelman's been ragging me to get data on what was buried at the bottom of the Pit. When the thing was finally drained, I thought maybe all the weird readings would vanish. But they didn't. No matter what I tried, I kept getting different readings every run. Until now. Take a look."
He held up the printout, an unintelligible series of black blobs and lines along with one fuzzy dark rectangle.
"What is it?" Hatch asked. "A Motherwell print?"
"No, man. It's an iron chamber, perhaps ten feet on a side and fifty feet below the cleared part of the Pit. Doesn't seem to have been broached by water. And I've just managed to narrow down its contents. Among other things, there's a mass of perhaps fifteen, maybe twenty tons of dense, nonferrous metal. Specific gravity just over nineteen."
"Wait a minute," Hatch said. "There's only one metal with that specific gravity."
Rankin's grin widened. "Yup. And it ain't lead."
There was a brief, electrifying silence. Then Bonterre shrieked with glee and bounded into Hatch's arms. Rankin bellowed again and pounded St. John's back. The foursome tumbled out of the hut, shouting and cheering.
As more people heard the commotion and came running, word of Rankin's discovery quickly spread. Immediately, a spontaneous celebration erupted among the dozen or so Thalassa employees still working on the island. The oppressive aftermath of the Wopner tragedy, the continuous setbacks, and brutally hard work were forgotten in a frantic, almost hysterical, jubilation. Scopatti capered around, removing his boat shoes and tossing them into the air, clutching his diving knife between his teeth. Bonterre ran into Stores and emerged with the old cutlass excavated from the pirate encampment. She ripped off a strip of denim from the base of her shorts and tied it around her head as an eyepatch. Then she pulled her pockets inside out and tore a long gash in her blouse, exposing a dangerously large swath of breast in the process. Brandishing the cutlass, she swaggered around, leering horribly, the image of a dissolute pirate.