By the year 48 B.C., when this novel takes place, the flawed Roman calendar had drawn some two months ahead of the actual seasons. Thus, although the story begins on the 27th of September by the Roman calendar, the season is actually high summer, and the date, by modern reckoning, is closer to the 23rd of July.

"There! Can you see it? The lighthouse!"

Bethesda gripped my arm and pointed to a sparkle of light on the dark horizon. It was the hour before dawn. The deck of the ship rocked gently beneath our feet. I squinted and followed her gaze.

All night Bethesda had stayed awake, awaiting the first glimpse of the great lighthouse of Alexandria. "It could be any minute now," the captain had told us the previous day at twilight, and Bethesda had staked a place at the prow of the ship, her gaze set on the southern horizon, where blue-green sea met azure sky. Slowly the blues darkened to deepest purple and then to black; the sky was pierced with stars, and starlight lit the face of the deep; a sliver of moon traversed the sky, and still the lighthouse did not appear. It seemed we were not quite as close to Alexandria as the captain thought, yet I trusted his navigation; the voyage from Rome had so far been quick and uneventful, and even I could tell from looking at the stars that our course was now due south. The steady breeze at our backs was taking us across a calm sea directly toward Egypt.

All night I stood beside Bethesda, joining in her vigil. The night was warm, but occasionally she shivered, and I held her close. Many years ago we had departed from Alexandria by ship, watching the flame atop the lighthouse for hours as it gradually dwindled and finally vanished from sight. Now we were returning to Alexandria, and again we stood together on a ship, scanning the horizon for a first glimpse of that same undying flame.

"There!" she said, this time in a whisper. I squinted uncertainly; might the glimmer of light be merely a star twinkling just above the water's edge? But no, the light was too steady to be a star, and as we watched, little by little it grew righter.

"Pharos," I whispered, for that was the name of the lighthouse, as well as the name of the island upon which it was built-the oldest and by far the greatest lighthouse in all the world. With the brightest flame ever produced by men, set atop the tallest tower ever built, for hundreds of years it had guided ships to Alexandria.

"Alexandria!" Bethesda whispered. She had been born there, and there I had met her during my travels as a young man. After I took her home with me to Rome, neither of us had ever returned. But no one forgets Alexandria. Over the years I had dreamed often of the city's broad avenues and magnificent temples. In the last few days, as the ship brought us ever nearer, memories had come flooding back in overwhelming profusion-not only sights and sounds but also flavors and smells and tactile sensations. I swooned, remembering waves of heat from the paving stones of the Canopic Way on a hot day, the dry kiss of a desert breeze through the palm trees, the cool refreshment of a swim in Lake Mareotis under the looming skyline of the city.

During the journey, Bethesda and I made a game of sharing memories, trading them back and forth like children playing tag. Either of us had merely to say a word to spark a memory that sparked yet more memories. Now, with the light of the Pharos twinkling in the distance, she squeezed my hand and whispered, "Scarab."

I sighed. "The jeweler with that little shop just down the hill from the temple of Serapis."

Bethesda nodded. "Yes, the one with the crooked nose."

"No, that was his assistant. The jeweler himself-"

"-had a bald spot and a wattle neck. Yes, I remember now."

"How could you forget, Bethesda? He accused you of stealing that scarab pendant from right under his assistant's crooked nose."

"The assistant's nose wasn't the only thing crooked about him. He was the one who took the scarab!"

"As I eventually discovered. The poor fellow should be finishing up his sentence in the salt mines about now."

"Poor fellow? He should never have allowed the blame to fall on an innocent girl." Her eyes flashed, and I saw a glimmer of the mischievous spirit that still dwelled in her, despite the terrible illness that had befallen her. I squeezed her hand. She squeezed it back, and my heart ached at the feebleness of her grip.

Bethesda's illness was our reason for coming to Egypt. For months it had plagued her, sapping her of strength and joy, eluding every cure propounded by every physician we consulted in Rome. At last Bethesda herself proposed a cure: She must return to Egypt. She must bathe in the waters of the Nile. Only then could she be made whole again.

How did Bethesda come to this knowledge? I had no idea. One morning she simply announced that we must be off to Alexandria. Having come into a bit of money, I had no excuse to refuse her. To act as our bodyguard, and because he originally came from Alexandria, we took with us the newest member of my household, a hulking young mute named Rupa. We also brought along my two slave boys, the brothers Mopsus and Androcles; their quickness and cleverness would hopefully outweigh their penchant for getting into trouble. We were the ship's only passengers. In such troubled times, few traveled who could possibly avoid it.

Rupa and the boys slept, as did most of the ship's crew. In the stillness of that final hour before dawn, it seemed that Bethesda and I were the only two people alive, and that the beacon of the Pharos, growing gradually, steadily brighter, shone for us alone.

Little by little the sky lightened. The sea's black luster faded to the color of slate. A faint red glow suffused the eastern horizon. The light of the Pharos seemed to grow fainter, outshone by the sudden flicker of red flame that announced the rising of Helios in his fiery chariot.

I sensed a change on the ship. I looked behind us to see that the deck was now swarming with sailors tending to ropes and riggings. How long had they been there? I seemed to have dozed while watching the dawn, yet I could have sworn that I never closed my eyes. The light of the Pharos had bemused me. I blinked and shook my head. I looked more closely at the sailors. Their expressions were grim, not joyful. Among them I saw the captain; his face was grimmest of all. He was an affable fellow, a grizzled Greek about my own age, sixty or so, and we had become friendly over the course of the voyage. He saw me staring and strode close by me on his way to bark an order at some of his men. Under his breath he muttered, "Red sky. Don't like it."

I turned toward Bethesda. Her eyes narrowed; her lips parted; she continued to stare at the beacon of the Pharos, oblivious to the commotion behind us. For the first time I could barely discern the tower of the lighthouse itself, a tiny sliver of pale stone beneath the bright point of light.

"So close!" Bethesda whispered.

We had only to stay on course and maintain a steady progress, and the tower of the Pharos would little by little grow larger and more distinct-to the height of a fingernail, a finger, a hand. We would begin to make out the fluted stonework that decorated its exterior; we would see the statutes of gods and kings that ornamented its base and the balconies of its upper reaches. Beyond the Pharos, we would see the crowded ships in the great harbor and the jumble of rooftops that made up the skyline of Alexandria.

I felt a tug at the sleeve of my tunic and turned to see little Androcles staring up at me. His slightly bigger brother, Mopsus, stood behind him, and looming over them was Rupa, rubbing the sleep from his eyes.