The heat inside the Murano fornace was a living, breathing beast. It was July of 1576, and while the city of Venice across the lagoon was suffocating under the heavy, humid shroud of summer, the glassworks were a roaring inferno.
Caterina Zeno wiped a sheen of sweat from her brow, her heavy linen sleeves rolled up past her elbows. She was twenty-one, with hair the color of roasted chestnuts and eyes as sharp as cut crystal. Women were strictly forbidden from mastering the art of the pontil pipe, but her father, Master Giovanni Zeno, had lost his sons to the plague. He had only Caterina, and her mind was a crucible of chemistry and mathematics that surpassed any man on the island.
“The flux, Caterina,” Giovanni rasped, his voice weak. The heat was taking its toll on his failing lungs. “It is time.”
Caterina nodded, stepping toward the roaring maw of the stone furnace. She wore thick leather gloves that smelled of charred wood and sulfur. In her hands, she held a small ceramic crucible containing a powder she had spent three years perfecting: chloride of gold.
In the Republic of Venice, glass was not merely art; it was a state secret. The flawless, clear cristallo brought immense wealth to the Doge. To leave the island of Murano with the knowledge of glassmaking was a crime punishable by death—the Council of Ten would dispatch assassins across Europe to slit the throats of defectors. But Caterina and her father were not making cristallo. They were chasing a myth. Rubino Oro. Blood-red glass.
Caterina carefully tipped the gold chloride into the molten vat of silica, soda ash, and lime. The mixture hissed violently, spitting sparks of brilliant white light.
“Now, Papa,” she urged.
Giovanni stepped forward, lifting his long iron blowpipe. He gathered a glowing gather of the molten mixture on the end, removed it from the furnace, and began to roll it on the iron marver table. He blew gently into the pipe. The glass expanded like a lung. As it cooled in the ambient air, the magic happened. The clear, glowing orb suddenly flared into a deep, agonizingly beautiful crimson. It was the color of a fresh ruby, perfectly translucent, capturing the firelight in a web of suspended gold.
“We did it,” Giovanni whispered, tears mixing with the sweat on his soot-stained cheeks. “The Emperor himself would empty his treasury for a single goblet of this.”
“We must document the cooling times,” Caterina said, rushing to her father’s leather-bound ledger. But as she dipped her quill into the inkwell, the heavy wooden doors of the fornace splintered open with a deafening crash.
Caterina spun around. Standing in the doorway, flanked by three guards wearing the black tabards of the Council of Ten, was Magistrate Vivaldi. He was a tall, skeletal man with cold, sunken eyes and a face that looked as though it had been carved from pale marble.
“Master Zeno,” Vivaldi purred, his gaze instantly locking onto the glowing crimson vase still attached to the blowpipe. “Rumors reached my ears across the lagoon. I see they were true. You have cracked the Rubino Oro.”
Giovanni lowered the pipe, his hands trembling. “Magistrate. This is a triumph for the Republic. I was planning to present it to the Doge tomorrow.”
“The Doge is a dying old man who cannot pay his armies,” Vivaldi sneered, stepping into the sweltering heat of the workshop. “The Ottoman Sultan, however, will pay a mountain of silver for the monopoly on this red glass. Give me the ledger, Giovanni.”
Caterina’s blood ran cold. Vivaldi wasn’t here to secure the glass for Venice. He was committing high treason. He was going to sell the greatest secret in Murano to the Republic’s greatest enemy.
“I will not betray my city,” Giovanni spat, his frail frame stiffening. “I will die first.”
“That can be arranged,” Vivaldi said casually. He nodded to his guards.
One of the men lunged forward, drawing a heavy Venetian stiletto. Caterina screamed as the blade buried itself in her father’s chest. Giovanni gasped, dropping the heavy iron blowpipe. The masterpiece of Rubino Oro hit the stone floor, shattering into a thousand brilliant, bloody shards.
“Papa!” Caterina threw herself toward him, but a guard struck her hard across the face, sending her crashing into the wooden workbench. Her vision swam.
“Find the ledger!” Vivaldi barked, stepping over Giovanni’s bleeding body.
Caterina looked up, her head ringing. The ledger was sitting openly on the desk beside her. Vivaldi’s men were tearing through the cabinets across the room. She knew if Vivaldi got the book, her father’s murder would go unpunished, and Venice would be betrayed.
With a surge of desperate adrenaline, Caterina grabbed the heavy leather ledger and hurled it directly into the roaring mouth of the furnace.
“No!” Vivaldi screamed as the book hit the molten silica. The dry parchment ignited instantly, dissolving into ash in a fraction of a second.
Vivaldi turned to Caterina, his face contorted in absolute, murderous rage. “You foolish girl. Do you know what you’ve just done?”
“I’ve memorized it,” Caterina spat, blood dripping from her split lip. “Every measure of flux, every ounce of gold salt. It is in my head. And you will never have it.”
Before the guards could grab her, Caterina kicked a massive barrel of cooling water over. The water flooded across the stone floor, hitting the red-hot bricks of the furnace. A massive, blinding cloud of thick white steam instantly filled the room.
Blinded, the guards coughed and cursed. Caterina didn’t hesitate. She scrambled through a small, open ventilation window at the back of the workshop, dropping into the dark, churning waters of the Murano canal just as Vivaldi ordered his men to cut her down. She swam into the blackness, the secret of the red glass burning safely within her mind.
