“Get down!” Cyprian shouted, pulling Radu flat. Radu covered his ears, but the explosion was still deafening. He felt the concussive force of the blast passing right through him. The world hung in stillness for one soundless moment. Then debris pinged against the barrels, against his back, falling everywhere.

The tower was on its side, ripped open. Men ran forward to help the fallen Ottomans, not accounting for the other barrels. Radu and Cyprian ducked again, two more blasts coming in quick succession.

The scent of gunpowder almost covered the stench of burning flesh.

Giustiniani stood, pointing to a group of soldiers standing at the ready behind a sally port. “Burn everything! Kill anyone still moving!”

The port was flung open and men ran out. It was quick work, killing any Ottomans still alive and stunned from the last explosion. They poured pitch onto what was left of the tower’s wooden frame and wheels. When lit, it burned so brightly that Radu could feel the flames warm his face.

Cyprian turned away from the killing, pulling his knees up and resting his head on them. His shoulders were shaking.

“Are you hurt?” Radu’s hand hovered above the other man’s arm. He did not dare touch him. Not on purpose, not in tenderness. He had defied Mehmed’s order to stay safe because he could not abandon Cyprian. And in doing so, he had helped defeat this newest, best chance at the end of the siege. How many ways could a man turn traitor in one lifetime?

Cyprian looked up. Radu could not tell if he was laughing or crying. “I really thought that would blow us up. I thought there was a very good chance I was taking down our own walls and letting him in.”

“But you tried it anyway?”

Cyprian wiped under his eyes, which left his face smeared with soot. “He is attacking us from every possible angle. Below the walls, outside them, above them. From the land, from the sea. He does not need everything to work. Just one thing. And eventually, something will.” Cyprian leaned his head back, looking up at the smoke above them. “But not tonight,” he whispered.

“But not tonight,” Radu echoed. He did not know if he said it in relief or in mourning.

Cyprian’s gamble paid off. When one tower fell, Mehmed pulled them all back. The bombardment continued unabated, but by now that felt almost normal.

Two days after the towers retreated, Cyprian received a summons to the palace. Radu was pulling on his boots to go back to the wall. Amal had not been at his place outside the Hagia Sophia. Radu had nothing but confessions and confusions to send to Mehmed anyway.

“My uncle has asked you to come, too,” Cyprian said.

Radu frowned, surprised. “Why?”

“He does not say.”

The small part of Radu’s soul that had not been beaten down under the bombardment feared that he had been discovered. Perhaps he was walking to his death. He caught Nazira’s eye from across the room. “Nazira, it seems quieter at the walls today. You should go over to Galata and see if there is any food you can buy there. Cyprian is losing weight.”

“I am not!” Cyprian forced his stomach forward and patted it.

“He looks terrible.” Radu smiled as though in jest but levied a meaningful look at Nazira. “Bring him some food from those beautiful fat Italians.”

“You look terrible.” Nazira narrowed her eyes and shook her head at Radu. “I am not going to Galata for anyone or anything. I will be right here when you come back from the palace.”

Radu walked up to her and placed a kiss on her forehead. “Please,” he whispered against her skin.

“Not without you.” Then she pulled back and smiled, reaching up to rub at the stubble on his face. “Both of you eat at the palace. Save me the trouble of making you a meal. And while you are at it, see if the emperor can spare a razor, too.”

With one last pleading look, Radu joined Cyprian. They walked in silence through the muddy streets. Though there were more religious processions than ever, they were fortunate enough not to run into any. Sometimes in his dreams Radu was stuck in the middle of one. Around the sound of the priest’s liturgy, the women wailed and the children cried, while the smoke of the censer clogged his eyes and nose until he could neither see nor breathe. When the smoke finally cleared, everyone around him was dead. But the liturgy continued.

“Are you well?” Cyprian asked. “You keep shuddering.”

Radu nodded. “Cold for May.”

“Do not tell anyone else that. They will find some prophecy or other that states that a cold May signals the end of the world.”

Radu tried to laugh but could not. If only Nazira had agreed to leave, he would feel at peace with facing his end. It was inevitable, at this point. He was always going to die here. He did not want her to.

At least he trusted that Cyprian was not the one who had figured it out. Cyprian wore his honesty painted across his face. If Radu was going to his death, Cyprian did not know it. It was poor comfort, but enough to give Radu the strength to keep moving, keep walking in this precious space before Cyprian found out the truth and never again looked at him with those beautiful gray eyes.

They passed several women and children dragging sacks full of rocks and rubble to repair the walls. When a stone cannonball shattered the wall of a house next to them, Radu and Cyprian ducked instinctively, before they had even processed what caused the noise.

The women and children had no such experience. One of the children lay in the street, broken and unmoving. A woman knelt over the child. She picked up the body and tucked it against the wall. “I will be back,” she said, her hands bloody. Then she retrieved her bag and the bag of the child, and continued on to the wall.

“How can we go on?” Cyprian whispered. “Is this hell?”

Radu took Cyprian’s hand, turning him away from the body of the child. The palace was before them. Radu knew it did not matter what he hoped or feared would happen. Death was unfeeling and random, as likely to strike down an innocent child as a guilty man.

They were met by two soldiers who escorted them past Constantine’s study. They moved deeper into the palace, and then through a courtyard into another building. It was colder than the palace, the rocks leeching warmth from the day. The air smelled of mildew and despair.

“Why are we going to the dungeons?” Cyprian asked.

Radu allowed himself one moment of true sorrow for Nazira. He had failed. At everything, at all of it, but at this one most important thing he had promised himself and God. I am sorry, he thought as a prayer. I am sorry. Save her.

“Prisoners,” one of the soldiers said, as though that explained everything.

When they emerged through a door at the bottom of a winding set of stairs, Constantine turned to face them. His face was hard. Next to him was Giustiniani. Radu took a deep breath, praying for strength. He met their gazes unflinchingly. He might still be able to barter for Nazira’s life.

“There you are. Come on.” Giustiniani gestured impatiently. Radu stepped forward, finally able to see past them.

Kneeling on the floor chained, bloodied, and dazed, was a man Radu had last seen being berated by his mother while delivering gunpowder. Tohin’s son, Timur. How was he here?

“He has been speaking Arabic,” Giustiniani said, “and we cannot understand him. Can you translate?”

“I should be able to. Where did he come from?” Radu asked, trying to control his voice.

“We caught him digging a tunnel under the walls. The rest were killed with Greek fire. Burned alive.”

“I am the lucky one,” Timur mumbled around a bloody, swollen tongue and broken teeth. He looked up at Radu and smiled. Radu did not know if the smile was one of recognition or madness.

Radu was not here to be tortured and killed. He was here to aid in the torture of a man he knew. A man with a family. Two children, he had spoken of. Or was it three? Radu could not remember. It seemed very important now to remember. I am sorry, he prayed again, this time with even more anguish. But Nazira was still safe. He held on to that light as a way to keep out of the darkness threatening to claim him.

Radu cleared his throat. “I know this man. His name is Timur. I met him briefly before fleeing the court.”

Giustiniani grunted. “We need the locations of all the other tunnels. My men have been working on him for a while, but he has not given us any information.” He pointed at a map of the walls. “Do whatever you can think of to get him to talk.”