Unknown 9, Layton Green [good books to read for 12 year olds txt] 📗

numbers and mathematical symbols on the paper he had lifted from the cellar. He had kept the matchbox too.

Though stumped at first, he solved the code before he finished the meal of rice, beans, and corn empanadas. The puzzle was laughably simple, at least for a professor of theoretical physics who excelled at mathematics. Sipping his beer, he discovered by trial and error the numbers on the sheet of paper were atomic numbers in the periodic table, all of which, of course, were represented by one or two letters of the alphabet. The mathematical symbols were basic ones—multiplication, division, square root. When the words he formed using the atomic numbers alone resulted in nonsense, he applied the mathematical symbols to the numbers in the standard order of operations before converting them to letters. Using the first letter of each symbol resulted in a phrase that made him tingle with excitement.

THIRD CANNON FROM NW WATCHTOWER

The cypher could refer to a thousand different fortifications around the world. But in Cartagena, it could mean only one thing: San Felipe Castle, the iconic fortress looming above the city.

Dr. Corwin discovered from the staff that the castle was only a short walk away but closed for the night. He decided against a hotel, in case the Ascendants were calling around. Instead he wandered the neighborhood until he found a homeless camp in a palm grove, then paid one of the men about his size a few dollars to exchange his soiled clothing for a hooded poncho, cotton trousers, and leather sandals with soles barely hanging on.

Wary of being robbed if he stayed overnight, he left the grove, found a comfortable park bench tucked out of view, and slept like a baby. There were hundreds, maybe thousands, of beggars and homeless people in the city with a build and skin tone just like his. It was a pleasant evening, so why not hide in plain sight?

The next morning, as soon as the entrance to San Felipe Castle was unlocked, Dr. Corwin watched the people around him gape as the homeless man in their midst rose off the park bench at the bottom of the castle, grabbed a coffee from a street vendor, paid the entrance fee, and proceeded to shuffle up the long switchback ramp to the top of the castle. Had the pedestrians gotten too close, their noses would have wrinkled at the awful smell of his poncho, and if their hearts were not hardened, they would have felt sorry for the threadbare state of his cotton trousers and the flapping soles on his sandals.

He wondered if they would have been more—or less—shocked to know the homeless man was actually a professor of theoretical physics at Columbia, slumming in rags to avoid the members of a dangerous secret society prowling the city looking for him.

San Felipe Castle was a mammoth structure. A quick glance at the entry pamphlet revealed it was the largest and most complex Spanish-built fort in the Americas. In the early days of exploration, Cartagena, as fat as a blood-filled tick with profits from slaves and gold, had been looted so many times by Sir Francis Drake, along with a long list of pirates, the Spanish got fed up and built a seven-mile wall around the city, studded with turrets and reinforced by forts at strategic locations. The greatest of these was San Felipe Castle, a feat of military engineering that included eight batteries, dozens of cannons, cisterns in case of drought, and a system of tunnels dug by Welsh miners and rigged with exploding ceilings. The system of interlocking walls, zigzagging entry ramps, parapets, and tower batteries with overlapping fields of fire made it impossible to isolate any one defensive section, making the castle a death trap to attackers and impregnable at the time. Despite numerous attempts, its walls were never breached, and it took mainland Europe half a century to catch up to the advanced geometry of the design.

The night before, Dr. Corwin had debated breaking into the castle. There would have been a certain irony in breaching walls that had repelled invaders for centuries. Yet he had no idea what sort of surveillance the city had in place, and most important of all, the Ascendants would have no reason to suspect his presence at the castle this morning—because the only clue was hiding in his pocket.

Following the decoded directions, he found the third cannon closest to the northwest watchtower. The cannon was pointing west, toward Cartagena Bay. Sky and sea merged into an azure shimmer in the distance.

The morning sun was potent, causing him to sweat and itch beneath the filthy poncho. He ignored the discomfort and bent to get a closer look. The cannon, which sat between pitted stone walls on a wheeled wooden cart in dire need of repair, had oxidized to a mottled blue-green color. A thorough inspection revealed no secrets, until he got down on his hands and knees and found a short message carved into the underside of the cart.

ADDIO. EM

The message caused a sinking feeling in the pit of his stomach. He stared at it, stunned and disbelieving, for a long time.

Dr. Corwin knew there were a number of ways to say goodbye in Italian. The very casual ciao was used for both hello and goodbye. Arrivederci was a slightly more formal salutation among friends and family, which translated to “until we see each other again.” There was buon viaggi for “have a good trip” and buongiorno for “have a nice day.”

Addio was the most permanent farewell of them all.

Addio meant you might not see the person again—ever.

He stood to survey the horizon in the direction the cannon was pointing. Did you go west, Ettore? Is the message a final farewell?

Or was this all a subterfuge to throw off pursuit?

Though bitterly disappointed, and confused as to the motive behind such a convoluted ruse, Dr. Corwin began to chuckle, and then laugh, at the perverse way Ettore had played him. Played them all.

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