Walking aimlessly, midway between the Library and Isidorus’s apartment I passed a tavern. On such a warm day, all the doors and shutters were open. I chanced to look inside, and in a far, shadowy corner I saw Isidorus. He sat facing the street, listening intently to a man who sat with his back to me. So eager was I to talk to someone about what I had seen and heard that I almost stepped into the tavern to join them. Then the man with Isidorus turned his head a bit to one side.

It was Nikanor.

*   *   *

That night at dinner, Antipater asked if I was unwell. I told him I was fine.

“Then stop fidgeting. One would think you were sitting on a needle. And you’ve eaten hardly a bite of the pomegranate salad. A loss of appetite is most unlike you, Gordianus.”

I shrugged.

“Nor have you even tasted the excellent wine to which Isidorus is treating us tonight. Imported all the way from Chios.”

I shrugged again. I was intentionally avoiding the wine. I wanted to keep my wits about me.

“Leave the young man in peace, friend Zoticus,” said Isidorus. His use of the false name set my teeth on edge. “Less of the Chian for him means more for us.”

The two of them shared a laugh and clinked their silver goblets.

I excused myself and headed for my room.

“Sleep well, Gordianus,” Antipater called after me. “In the morning, I may have a surprise for you.”

As I stepped into my room, I heard Isidorus whisper, “Do you think he’s sick?”

“Lovesick, more likely. Some pretty thing must have caught his eye and spoiled his appetite. Ah, to be his age again. I am reminded of a verse—”

Rather than hear him declaim, I shut the door, fell into bed, and covered my head with pillows. Time passed. My mind was a dull, aching void. I threw the pillows aside, returned to the door, and quietly opened it. Antipater and Isidorus were still talking, so quietly I could barely hear them.

“Nikanor has become a liability,” said Antipater. “I told you what he did in Olympia, killing that wretched Cynic. I’d known poor Simmius when we were boys together in Sidon, but we hadn’t seen each other in fifty years, and he was surely no more an agent of Rome than I am! But Nikanor became convinced that Simmius had recognized me, and would expose me, so on his own initiative Nikanor murdered Simmius—never considering what might happen if he was caught, and his affiliation with Mithridates came out. I might have been exposed along with him, putting an end to my usefulness when I’d hardly begun. Nikanor was always reckless. Now he sees spies and infiltrators everywhere. I think he’s gone mad.”

Hackles rose on the back of my neck. There could be no doubt: Antipater was an agent of Mithridates. I had no time to think, for Isidorus was talking and I felt compelled to listen.

“You can question Nikanor’s judgment, but not his loyalty,” he was saying. “No one has made greater sacrifices, traveled greater distances, or taken more risks for the cause than Nikanor—not even you, Antipater.”

“You’re not listening to me, Isidorus. It’s not his judgment I question—it’s his sanity. He says things that make no sense. What was it he told you about the Pharos today? Something about using the mirrors to gaze into the royal palace, and to read King Ptolemy’s mind?”

“He does have strange notions—”

“He’s crazy, Isidorus. He was always a little crazy, but now he’s become more so—to a degree that poses a danger to us all.”

Isidorus sighed. “Unfortunately, he’s my only trustworthy go-between for communicating with Anubion at the Pharos. You said yourself, the very day you arrived, that establishing a system of signals using the Pharos must be our highest priority. Once war breaks out between Rome and Mithridates, what if the Romans invade Egypt? Our ability to communicate in secret will be absolutely vital.”

“The Romans will never occupy Alexandria,” said Antipater.

“Perhaps not. But even if Egypt stays out of the war, Alexandria will be crawling with spies. The Romans are children when it comes to setting up secret operations. Mithridates is a master at such things, and that may be his greatest advantage. Our ability to use the Pharos to communicate in secret could mean the difference between victory and defeat.”

“Let’s not get carried away, old friend—you’re beginning to sound as grandiose as Nikanor.”

Isidorus laughed softly. “All my life, I’ve been nothing more than a scribbler in the birdcage of the Muses. The idea that I could do something to change the world is a bit intoxicating, I must admit.”

“Rather like this fine Chian wine. Shall we finish it?”

“No, I’ve drunk too much already. I’m off to bed. We have a busy day ahead of us. Are you still determined to take Gordianus along with us?”

“If he finds out that I’ve been to see the Pharos without him, I shall be at a loss to explain why I didn’t take him along. Don’t worry, I’ll see that he stays out of the way while you confer with Anubion. Gordianus is young and easily distracted.”

“You’re certain that he suspects nothing of your mission?”

“Not a thing. As Gordianus has demonstrated repeatedly during our travels, he’s quite clever in some ways, but terribly naive in others. He’s smart, but not yet cynical. He still has a boy’s faith in his old tutor; it’s rather touching, actually. He’s never pressed me about my reasons for traveling incognito, and I’m quite sure he has no idea of my activities in every place we’ve visited—studying the local sentiments, seeking out and conferring with those who might be useful to our cause, making a list of those who pose a danger to us.”

“Even in Babylon?”

“Especially there! The Parthians are suspicious of both Rome and Mithridates, but when the time comes, they must be persuaded to take our side.” Antipater sighed. “Ah well, if there’s to be no more Chian wine, then I too am off to bed.”

As they rose and moved toward their separate rooms, I heard Isidorus whisper: “Rome is the disease.”

Antipater whispered back: “And Mithridates is the cure!”

I silently closed the door and returned to my bed.

My head was so filled with painful thoughts that I imagined it might burst. From the very beginning of our journey, Antipater had deceived me. What a fool I had been, never to see through him!

Perhaps I had not wanted to see the truth.

In Olympia, on the night before Simmius the Cynic was murdered, I had overheard two men talking in the tent of our host. One had been Nikanor. The other had spoken in such a low voice that I could not discern what he said, much less recognize his voice. Now I knew that the other man had been Antipater—and both were agents of Mithridates.

Thinking back, I remembered all the times in all the cities when Antipater had supposedly kept to his room while I went out for the day … or said he was meeting with fellow scholars to talk about poetry (knowing that nothing was more certain to send me away) … or went to some temple without me, since I had already visited the place and did not care to see it again. How many of those times had his actual purpose been a meeting with confederates to plot the rise of Mithridates and the ruin of Rome?

What schemes had he hatched with Eutropius in Ephesus, and with Posidonius in Rhodes, and with all the others he must have met in all the stops we made at Athens, Delos, Lesbos, and elsewhere?

In Halicarnassus, during all those blissful hours I spent with Bitto, I had presumed that Antipater was immersing himself in the volumes of her library—when in fact he must have been carrying on a furious correspondence with his contacts all over the Greek world. I had been oblivious. How had Antipater just described me? “Young and easily distracted.”

He and Isidorus were old friends—their conversation made that clear—but for my benefit they had pretended to be strangers on the boat that brought us to Alexandria. How many times had such charades been carried out right in front of me? And now, every day, when the two of them went to the Library, presumably to engage in esoteric research amid the dusty scrolls, they were devising a code that could be used to send secret signals from the Pharos.