Halil’s options were dwindling, and would dwindle further when his allies in Constantine’s court heard that a tower built on their land bore Halil’s name.

Secrets made information more powerful and suspect. The best way to keep the fortress safe from Halil’s machinations was to make him intimately—and inescapably—involved in its construction. It was the same method Radu was applying to the artillery, inspired by Nazira and Fatima’s relationship. Hiding in plain sight.

“What is so funny?” Urbana said, scowling. “I did not understand any of that. Why are you smiling?”

“Because I am pleased with tonight’s events.”

She sighed, picking at the bones of the unfortunate fowl on her plate. “I still do not understand why I have to be here. We never even speak to the sultan.”

“You are here so that everyone sees you are my special project. I want the whole city gossiping about how foolish I am, hiring a woman to make the largest cannon in the world to try to impress the sultan. I intend to subject us both to ridicule.”

Her scowl deepened. “Why would you do that?”

“So that no one pays any attention until we succeed.”

For the first time that night, Urbana smiled. She snapped a bone off the chicken.

Radu nudged her with his elbow. “Imagine how surprised they will be when the sultan has the most advanced artillery in the world, built by a woman and the most handsome and useless foreigner in the empire.” He stood. “Come. I need to introduce you to everyone, and tell them how we are designing a cannon so big it could puncture a hole in the bottom of the Black Sea and drain it dry.”

Urbana grimaced but nodded. “Lead on.”

Later that week, Radu pulled aside the tapestry to leave his update on Urbana’s progress and the navy’s readiness. He was so shocked to find Mehmed sitting in the room that he barely stifled a cry.

“Radu.” Mehmed grinned. “You are very late.”

“I— What is wrong?”

“Nothing. I have something for you.” Mehmed held out a letter.

It was addressed to Radu in a hand like someone had taken a blade and dipped it in ink. The part of his heart that was permanently vacant hurt as it beat again. He turned the parchment over to find it had been sealed by a knife tip pressed into wax.

“Lada,” he whispered, running his fingers over the red seal.

“It arrived this morning.” Mehmed’s voice was carefully neutral. “Did you write her?”

“Yes, after I found out she was not on the throne. I had given up hope that the messenger would ever find her.”

Radu would have preferred to read privately, but he could not bear to leave this gift of time with Mehmed. But the way Mehmed’s eyes were fixed on the letter, like a starving man on a circle of bread, hurt. All this time they had spent apart, all these times he had never been waiting for Radu.

Mehmed was here only for Lada.

He was still in love with her. They never spoke of her, but it was inescapable. Perhaps, since she left before Mehmed could claim her, he would long for her forever. The same way he was fixated on Constantinople, simply because it was not his but he felt it should be.

According to Islam, though, Mehmed could not consummate his relationship with Lada. It was forbidden outside of marriage or official concubines. Lada had been inside Mehmed’s harem, though, which legally made her part of it.

There was always a way forward for Mehmed and Lada.

Radu hung his head. What did he hope his future would be? To stand forever at Mehmed’s side, beloved friend, trusted advisor? He had told Nazira it would be enough. It would never be enough.

Mehmed put a hand on Radu’s shoulder. The jolt of the touch went so much deeper than the light pressure of his fingers. “Are you well, my friend?”

Radu cleared his throat, nodding. He tore open the letter with more force than was needed. It was addressed, in typically sentimental style, to My only brother, Radu. It had been more honest than his greeting to her.

“What does she say?” Mehmed asked, perfectly still. He may as well have been bounding around the room, for all his stillness hid his anxiety.

Radu read aloud, his voice flat from the exhaustion of his emotions.

“I was surprised to receive your letter. I am sorry to report that the messenger you sent is dead. I did not kill him. I suppose, in a way, you did, for sending him here.”

Radu paused, narrowing his eyes in annoyance both at Lada’s words and at the fact that she might have a point. Had he sacrificed a life simply to send a letter to his sister?

“She teases you,” Mehmed said. “I am sure the messenger is fine. Go on.”

“In turn, I will surprise you by telling you I am with Hunyadi. He found me in Transylvania and we declined to murder each other. I wondered if I was being disloyal to our father and brother, but they are dead and so cannot complain. He invited my company to join his.

“I do not know his motives, but I accepted. I will finally have an ally worth something. If I can convince Hunyadi to support me, I can take the throne. I know it. But after that, I do not have the skill for nobility. I am a blunt weapon. I need a surgeon.

“I am tired of being the right hand to powerful men. I want you as my right hand. I have seen you move among nobility as easily as a hawk cuts through the air. Cut through the boyars for me. Come home, Radu. Help me. Wallachia belongs to us, and I will not be complete without you.”

Radu paused, shocked. “And then she signs her name.” He did not say how she signed it.

Lada, on the ice and in need of your hand this time.

With one line she had dragged him back to his helpless childhood, when he had needed rescuing after going out too far on the ice. And—he could not quite believe it—she was asking him for help.

She recognized that he was good at something she was not. Mehmed had been right. Lada needed him to secure her path to power. For a few silent, painful moments, he considered it. She was his sister. She had never asked him for anything. She had expected him to come along initially, because she thought he should, not because she wanted him to.

Now, though …

“Will you go to her?”

Radu looked up, surprised. Mehmed’s voice was as quiet as his own had been, as carefully devoid of emotion. But Radu knew his friend’s face better than anything on earth. He had studied it, worshipped it. And Mehmed could not hide his fear and anguish.