The pestilence came first to the town of Kaffa on the Black Sea. There the mighty Mongolian Tartars waged siege upon the Italian Genoese, merchants and traders. Plague struck the Mongol armies with burning boils and bloody expulsions. Struck with great malice, the Mongol lords used their siege catapults to cast their diseased dead over the Genoese walls, and spread plague in a litter of bodies and ruin. In the year of the incarnation of the Son of God 1347, the Genoese fled under sail in twelve galleys back to Italy, to the port of Messina, bringing the Black Death to our shores.

— DUKE M. GIOVANNI (1356), trans. by Reinhold Sebastien in Il Apocalypse (Milan: A. Mondadori, 1924), 34–35

Why the bubonic plague suddenly arose out of China’s Gobi desert during the Middle Ages and slew a third of the world’s population remains unknown. In fact, no one knows why so many plagues and influenzas of the last century — SARS, the Avian Flu — have arisen out of Asia. But what is known with fair certainty: the next great pandemic will arise again out of the East.

— United States Centers for Disease Control and Prevention, Compendium of Infectious Diseases, May 2006

Herein lies a mystery. In the year 1271, a young seventeen-year-old Venetian named Marco Polo left with his father and uncle on a voyage to the palaces of Kublai Khan in China. It was a journey that would last twenty-four years and bring forth stories of the exotic lands that lay to the east of the known world: wondrous tales of endless deserts and jade-rich rivers, of teeming cities and vast sailing fleets, of black stones that burned and money made of paper, of impossible beasts and bizarre plants, of cannibals and mystic shamans.

After serving seventeen years in the courts of Kublai Khan, Marco returned to Venice in 1295, where his story was recorded by a French romanticist named Rustichello, in a book titled in Old French Le Divisament dou Monde (or The Description of the World). The text swept Europe. Even Christopher Columbus carried a copy of Marco’s book on his journey to the New World.

But there is one story of this journey that Marco refused to ever tell, referring only obliquely to it in his text. When Marco Polo had left China, Kublai Khan had granted the Venetian fourteen immense ships and six hundred men. But when Marco finally reached port after two years at sea, there remained but two ships and only eighteen men.

The fate of the other ships and men remain a mystery to this day. Was it shipwreck, storms, piracy? He never told. In fact, on his deathbed, when asked to elaborate or recant his story, Marco answered cryptically: “I have not told half of what I saw.”

The screams had finally ceased.

Twelve bonfires blazed out in the midnight harbor.

“Il dio, li perdona…” his father whispered at his side, but Marco knew the Lord would not forgive them this sin.

A handful of men waited beside the two beached longboats, the only witnesses to the funeral pyres out upon the dark lagoon. As the moon had risen, all twelve ships, mighty wooden galleys, had been set to torch with all hands still aboard, both the dead and those cursed few who still lived. The ships’ masts pointed fiery fingers of accusation toward the heavens. Flakes of burning ash rained down upon the beach and those few who bore witness. The night reeked of burned flesh.

“Twelve ships,” his uncle Masseo mumbled, clutching the silver crucifix in one fist, “the same number as the Lord’s Apostles.”

At least the screams of the tortured had ended. Only the crackle and low roar of the flames reached the sandy shore now. Marco wanted to turn from the sight. Others were not as stout of heart and knelt on the sand, backs to the water, faces as pale as bone.

All were stripped naked. Each had searched his neighbor for any sign of the mark. Even the great Khan’s princess, who stood behind a screen of sailcloth for modesty, wore only her jeweled headpiece. Marco noted her lithe form through the cloth, lit from behind by the fires. Her maids, naked themselves, had searched their mistress. Her name was Kokejin, the Blue Princess, a maiden of seventeen, the same age as Marco had been when he started the journey from Venice. The Polos had been assigned by the Great Khan to safely deliver her to her betrothed, the Khan of Persia, the grandson of Kublai Khan’s brother.

That had been in another lifetime.

Had it been only four months since the first of the galley crew had become sick, showing welts on groin and beneath the arm? The illness spread like burning oil, unmanning the galleys of able men and stranding them here on this island of cannibals and strange beasts.

Even now drums sounded in the dark jungle. But the savages knew better than to approach the encampment, like the wolf shunning diseased sheep, smelling the rot and corruption. The only signs of their encroachment were the skulls, twined through the eye sockets with vines and hung from tree branches, warding against deeper trespass or foraging.

The sickness had kept the savages at bay.

But no longer.

With the cruel fire the disease was at last vanquished, leaving only this small handful of survivors.

Those clear of the red welts.

Seven nights ago the remaining sick had been taken in chains to the moored boats, left with water and food. The others remained on shore, wary of any sign among them of fresh affliction. All the while, those banished to the ships called out across the waters, pleading, crying, praying, cursing, and screaming. But the worst was the occasional laughter, bright with madness.

Better to have slit their throats with a kind and swift blade, but all feared touching the blood of the sick. So they had been sent to the boats, imprisoned with the dead already there.

Then as the sun sank this night, a strange glow appeared in the water, pooled around the keels of two of the boats, spreading like spilled milk upon the still black waters. They had seen the glow before, in the pools and canals beneath the stone towers of the cursed city they had fled.

The disease sought to escape its wooden prison.

It had left them no choice.

The boats — all the galleys, except for the one preserved for their departure — had been torched.

Marco’s uncle Masseo moved among the remaining men. He waved for them to again cloak their nakedness, but simple cloth and woven wool could not mask their deeper shame.

“What we did…” Marco said.

“We must not speak of it,” his father said, and held forth a robe toward Marco. “Breathe a word of pestilence and all lands will shun us. No port will let us enter their waters. But now we’ve burned away the last of the disease with a cleansing fire, from our fleet, from the waters. We have only to return home.”

As Marco slipped the robe over his head, his father noted what the son had drawn earlier in the sand with a stick. With a tightening of his lips, his father quickly ground it away under a heel and stared up at his son. A beseeching look fixed upon his visage. “Never, Marco…never…”