I held on for dear life. Once we were over the crest, my mount locked her forelegs and slid down the slope, her shoulders as rigid as stone while her hind legs kicked and stamped against the furrowed earth. She shook her head and whinnied, like a warrior screaming to his gods to steel himself for battle.

The desperate descent uprooted bushes and set off avalanches of pebbles and sand. Suddenly a half-buried boulder loomed directly below me. For an instant I saw the features of Pluto himself in its weathered face, grinning at me horribly; we would collide with the stone and be shattered to bits. Closer and closer we came to it, and then my mount gave a great leap and bounded over it.

She landed with a jolt that nearly snapped my neck. There was no more sliding with locked forelegs; she had no choice but to gallop full speed down the steep face of the hill. I fell forward, clutched her neck, and dug my heels into her hide. Sky became wind; the earth became a cloud of dirt. The whole world was a ball rumbling through space. All balance was gone. I shut my eyes, clutched the beast as tightly as I could, and sucked in the odour of torn earth, horse sweat, and blind panic.

Suddenly the plummet became a gradual curve. Little by little the earth became flat again. We raced with the accumulated speed of the descent, but no longer out of control. The world righted itself; sky was sky and earth was earth. I squinted into the wind and slowly asserted control, reining the beast in. I half expected her to throw me out of anger and distrust, but she seemed glad for the reassurance of my hands on the reins. She shook her head and whinnied again, and it sounded as if she were laughing. She submitted and slowed to a trot, flinging spumes of sweat from her mane.

Alexandros was far ahead of me. I turned and caught a glimpse of Eco close behind. I sped onward toward the arena.

We raced between the tents. Soldiers in tunics satin circles gambling, or played trigon stripped to the waist, enjoying their holiday. They scattered before us and shook their fists in alarm. We raced past the spits and ovens with their plumes of white smoke, kicking dust into the flames. The cooks chased after us, screaming curses.

Alexandros waited for me outside the arena, his face confused and uncertain. I pointed to the north, where I had seen the red canopy and the pennants that decorated Crassus's private box. We set off at a gallop. Eco had fallen far behind. I waved to him to follow us.

The periphery of the arena was mostly deserted, except for a few patrons who had left the stands to relieve themselves against the wooden wall. Entrances opened onto steps that led upward to the seats, but I gestured to Alexandros that we should ride on until we found the steps that would take us directly to Crassus's box.

At the northernmost end of the circle we came to an opening smaller than the others and flanked by red pennants that bore in gold the seal of Crassus. Alexandros reined his beast and looked at me quizzically. I nodded. He leaped from his horse. I rode a few paces farther and peered as best I could around the edge of the arena; outside the eastern rim the soldiers were still forming ranks and had not yet entered.

I rode back to Alexandros. Above us, on the rim of the arena, a movement caught my eye. I looked up but saw only a face that quickly disappeared.

I dismounted, and almost fell to my knees. In the mad descent down the hill and the race through the camp I had felt no pain or dizziness, but as soon as my feet touched the earth my knees went weak and the throbbing returned to my temples. I staggered and steadied myself against my hone. Alexandros, already bounding up the steps, turned and ran back to me. I reached up to my forehead, touched the bandage, and felt a spot of warm wetness. I pulled my hand away and saw something red and viscous on my fingers. I was bleeding again.

From somewhere behind me, between the pounding drumbeats in my head, I thought I heard a boy calling, 'Papa! Papa!'

Alexandros clutched my arm. 'Are you all right?'

'Just a little dizzy. A little nauseous…'

Again I heard an unfamiliar voice calling, 'Papa, Papa,' louder and closer than before. I turned my head, thinking I must be in a dream, and saw Eco riding toward us, pointing to the sky. 'There!' he screamed, above the trampling hooves of his mount. 'A man! A spear! Watch out!'

I looked upward, over my shoulder. Alexandros did the same. An instant later he tackled me and we tumbled onto the ground. I was amazed at his strength, alarmed at the jolt of pain that ricocheted through my head, and only vaguely aware of what I had glimpsed above us – a man with a spear leaning over the arena wall. In the next instant the spear came plummeting down with a whistling noise and planted itself in the earth, missing my horse by less than a hand's width. Had Alexandros not pulled me to safety the spear would have entered the back of my neck and exited somewhere below my navel.

It took only a moment to vomit. The yellow bile left a bitter taste in my mouth and a mess all over the front of my tunic, but I felt vaguely better afterwards. Alexandros impatiently grabbed one shoulder while Eco grabbed the other. Together they pulled me to my feet.

'Eco!' I whispered. 'But how?'

He looked at me, but did not answer. His eyes were glassy and feverish. Had I only imagined it?

Then they were pulling me up the steps. We came to a landing and doubled back, came to another landing and doubled back again. We stepped onto thick red carpeting and emerged into bright sunlight filtered through a red canopy. I saw Crassus and Gelina seated side by side, flanked by Sergius Orata and Metrobius. I heard the slithering noise of steel unsheathed as Mummius stepped from behind Crassus and bellowed, 'What in Jupiter's name!'

Gelina gasped. Metrobius grasped her arm. Orata gave a start. Faustus Fabius, standing behind Gelina's chair, gritted his teeth and stared down at us with flaring nostrils. He lifted his right hand and the rank of armed soldiers at the back of the canopy took up their spears. Crassus, looking at once unpleasantly surprised and resigned to unpleasant surprises, scowled at me and lifted a hand to keep everyone in place.

I looked dizzily around, trying to orient myself. Red draperies hung from the canopy overhead, hiding us from the spectators immediately on either side, but beyond the edge of the draperies I could see the great circling bowel of the arena, jammed with people from top to bottom. Nobles sat in the lower tiers while the common people were crowded into the seats higher up. To separate them a long white rope circled the arena, running from one side of Crassus's box back around to the other.

Directly before the canopied box, down in the arena, huddled on the sand amid pools of blood, were the slaves. Some were in filthy rags; others, the last to have been taken from the household, still wore tunics of clean white linen. They were male and female, old and young. Some stood as still as statues while others listlessly turned and turned, looking about in fear and confusion. Each held a blunt wooden sword. How must the world have looked from where they stood? Blood-soaked sand beneath their feet, a high wall surrounding them, a circle of leering, laughing, hateful faces staring down at them. They say a man cannot see the gods from the floor of an arena; he looks up and sees only the empty blue sky.

I saw Apollonius among them, his right arm encircling the old man he had comforted in the annexe. I searched the crowd for Meto and did not see him; my heart skipped a beat and for an instant I thought he must somehow have escaped. Then he stepped into an open space near Apollonius, ran to him, and hugged his leg.

'What is the meaning of this?' said Crassus dryly.

'No, Marcus Crassus!' I shouted and pointed into the arena. 'What is the meaning of this?'