“Look, Ezio, when the news reached them of della Rovere’s elevation to the Papacy and then, on top of that, Cesare’s arrest, the old Borgia army probably scattered like ants from a nest when you pour boiling water into it.”

“I won’t rest easy until I know Cesare is dead.”

“Well, there is a way to find out.”

Ezio looked at Leonardo. “The Apple, do you mean?”

“Where is it?”

“Here.”

“Then get it, let’s consult it.”

Ezio hesitated. “No. It’s too powerful. I must hide it forever from mankind.”

“What, a valuable thing like that?” Leonardo shook his head.

“You said yourself, many years ago, that it should never be allowed to fall into the wrong hands.”

“Well, then, all we have to do is keep it out of the wrong hands.”

“There is no guarantee that we can always do that.”

Leonardo looked serious. “Look, Ezio—if you ever do decide to bury it somewhere, promise me one thing.”

“Yes?”

“Well, two things. First, hang on to it for as long as you need it. You need to have all you can on your side if your goal is finally to eradicate the Borgia and the Templars forever. But when you’ve done, and you do hide it from the world, then think of it as a seed that you plant. Leave some kind of clue as to its whereabouts for such as may be able to find it. Future generations—perhaps future Assassins—may have need of the Apple’s power—to use it on the side of Good.”

“And if it fell into the hands of another Cesare?”

“Back on Cesare, I see. Listen, why not put yourself out of your misery and see if the Apple can offer you any guidance?”

Ezio wrestled with himself for a few moments longer, then said, “All right. I agree.”

He disappeared for a moment and then returned, holding a square box, lead-covered and closed with a massive lock. He took a key, tied to a silver chain around his neck, from within his tunic and opened the box. There, on a bed of green velvet, lay the Apple. It looked drab and grey, as it always did when inert, the size of a small melon and a texture that was curiously soft and pliant, like human skin.

“Ask it,” urged Leonardo, his eyes keen as he saw the Apple again. Ezio knew his friend was fighting down a desire to grab the thing and run, and he understood how great the temptation was for the polymath, whose thirst for knowledge at times almost overwhelmed him and never let him rest.

He held the thing up and closed his eyes, concentrating his thoughts, formulating the questions. The Apple began to glow almost at once. Then it began to throw images onto the wall.

They came fast and did not last long, but Ezio—and Ezio alone—saw Cesare break from his prison and make his escape from Rome. That was all, until the inchoate images on the wall coalesced to show a busy seaport, the water shining and glittering beneath a southern sun, and a fleet in the harbor. The vision dissolved, and then there was a view of a distant castle, or perhaps a fortified hill town, far away, as Ezio somehow knew, and, judging from the landscape and the heat of the sun, certainly not in the Papal States of Italy. The architecture, too, looked foreign, but neither Ezio nor Leonardo could place it. Then Ezio saw Mario’s citadel at Monteriggioni, and the picture moved and shifted to take him to Mario’s private, secret study—the Sanctuary—where the Codex pages had been assembled. The concealed door to it was closed, and on the outside of it Ezio could see arcane figures and letters written. Then it was as if he were an eagle flying, flying over the ruins of the Assassins’ former stronghold. Then, abruptly, the Apple went dead, and the only light in the room was once again provided by the calm sunlight.

“He will escape! I have to go!” Ezio dropped the Apple back into its box and stood so abruptly that he knocked his chair over.

“What about your friends?”

“The Brotherhood must stand, with or without me. That is how I have built it.” Taking it from its box again, Ezio placed the Apple in its leather bag. “Forgive me, Leo—I have no time to waste.” He already had his hidden-blade and his bracer strapped on. He packed the pistol and some ammunition in his belt wallet.

“Stop. You must think. You must plan.”

“My plan is to finish Cesare. I should have done it long ago.”

Leonardo spread his hands. “I see that I cannot stop you. But I have no plans to leave Rome, and you know where my studio is.”

“I have a gift for you,” said Ezio. There was a small strongbox on the table between them. Ezio laid a hand on it. “Here.”

Leonardo rose. “If this is goodbye, then keep your money. I do not want it.”

Ezio smiled. “Of course it isn’t goodbye, and of course you want it. You need it, for your work. Take it. Think of me as your patron, if you like, until you find a better one.”

The two men hugged each other.

“We will see each other again,” said Ezio. “You have my word. Buona fortuna, my oldest friend.”

What the Apple had predicted could not be emended, for the Apple showed the future as it would be, and no man or woman could alter that, any more than he or she could change the past.

As Ezio approached the Castel Sant’Angelo, he could see papal guards, the new ones who wore the livery of Julius II, running out of the ancient fortress and dispersing in organized bands across the river and down the surrounding streets. Bells and trumpets rang out a warning. Ezio knew what had happened, even before a breathless captain he stopped told him:

“Cesare’s escaped!”

“When?”

“The guards were being changed. About half an hour ago.” Half an hour! Exactly the time when the Apple had shown it happening!

“Do you know how?”

“Unless he can walk through walls, we have no idea. But it looks as if he had friends on the inside.”

“Who? Lucrezia?”

“No. She hasn’t stirred from her apartments since all this blew up. But the Pope’s had her under house arrest since he took power. We’ve arrested two guards who used to work for the Borgia. One’s a former blacksmith. He might have been able to jimmy the lock, though there’s no sign of damage to the cell door, so they probably just used the key. If they’re guilty.”

“Is Lucrezia giving any trouble?”

“Strangely, not. She seems…resigned to her fate.”

“Don’t trust her! Whatever you do, don’t be lulled into a sense of false security by her manner. When she’s quiet, she’s at her most dangerous.”