"But to mount an assault, you need to wheel your towers and siege engines right up to the walls. If the ground isn't level-and it's certainly not level in that valley down there-you've got to make it so. That's why Caesar ordered the building of a massive embankment at a right angle to the wall, a sort of elevated causeway. It took a lot of leveling before we could lay the foundation; you'd think we were building an Egyptian pyramid from the amount of earth we've moved. The embankment is made mostly of logs, stacked up and up and up, each level perpendicular to the one below, with earth and rubble packed into the interstices to make it solid. Where it cuts across the deepest part of the valley, the embankment's eighty feet from top to bottom.

"All the time this digging and building has been going on,

the Massilians have kept firing on us from the walls, of course. Caesar's men are used to fighting Gauls, who've got nothing bigger than spears and arrows and slingshots. It's another game altogether with these Massilians. The hard fact is, though I hate to admit it, their artillery is superior to ours. Their catapults and ballistic engines shoot farther and shoot bigger. I'm talking about twelve-foot feathered javelins raining down on the men while they're trying to stack heavy logs! Our usual protections-movable shields and mantlets-were totally inadequate. We had to build lean-tos all along the embankment to protect the workers, stronger than any such structures we'd built before. That's what I love about military engineering-always a new problem to solve! We built the lean-tos from the stoutest wood we could find, armored them with pieces of timber a foot thick, and covered everything with fireproof clay. Boulders roll off like hailstones. Giant javelins bounce back as if they'd struck solid steel. Still, the racket inside those lean-tos, with missiles and stones crashing down, can certainly set your teeth on edge! I know; I spent my share of time down there overseeing the work.

"Once the embankment was almost done, we set about building a siege tower mounted on rollers, with a battering-ram built into the lower platform. It's down there now, at this end of the embankment. Tomorrow it will sally forth across the causeway, and there's no way the Massilians will be able to stop it. The men on the upper platforms of the siege tower are protected by screens of hempen mats too thick for any missile to penetrate. Once the tower is flush against the wall, the men on the upper platforms can fire down on any Massilians who venture out of the city to try to stop the operation, while the men on the lower platform can swing the battering-ram at will. Do you know what sort of panic that causes in a besieged city-the boom, boom, boom of a battering-ram striking the walls? You'll be able to hear it for miles."

I peered down into the valley. Amid shades of gray and black 1 could make out the straight line of the embankment traversing the valley from a point just below us to the base of the city walls. I could also make out the hulking mass of the siege tower at the nearer end. "But I thought you said that catapults and battering-rams would never bring down the walls of Massilia."

"So I did." Vitruvius grinned. "I really should say no more."

I raised an eyebrow. "The battering-ram is only a diversion?"

He was too proud of the scheme to deny it. "As I said, the sappers will have all the glory. They've been furiously tunneling since the first day we made camp. They've created a whole network of tunnels, running all up and down the walls. The longest is over that way." He pointed to the left, in the general direction of the main city gate and the harbor beyond. "By all our calculations, the diggers will break through tomorrow. In the blink of an eye, we shall have an opening inside the city walls. Just behind the diggers, troops will be packed inside the tunnel, waiting to pour out of that hole in the ground like ants from a stirred anthill. From inside Massilia, they'll rush the main gate. The Massilians will have concentrated all the men they can muster elsewhere, at the point where the siege tower and the battering-ram are assaulting the wall. An attack on the gate, from inside the city, will take them completely by surprise. The gate will be ours; and once our men have opened it, Trebonius himself will lead the charge into the city. The siege will be over. The Massilians will have no choice but to surrender and plead for mercy."

"And will Trebonius give them mercy?"

"Caesar's orders were to take the city and hold it for him until he returns. He intends to dictate terms to the Massilians himself."

"So there'll be no massacre?"

"No. Unless the Massilians are mad enough to fight to the death. Unlikely-they're merchants at heart-but you never know. Or unless…"

"Yes?"

"Unless our men get out of control." From the way his voice dropped, I knew he had seen such occurrences before. Meto had told me of Gaulish cities sacked and pillaged by Roman soldiers run amok. It seemed unthinkable that such a thing could be done to the people of Massilia, Rome's ally for centuries. But this was war.

Vitruvius smiled. "So now you see why I can't sleep, waiting for tomorrow."

I nodded glumly. "I thought a walk and some fresh air might help, but now-I don't think I'll be able to sleep either." Tomorrow, if Vitruvius was right, Massilia would be opened. Why, then, did Trebonius insist on sending me away? What did he know about Meto that I did not? Was he sparing me the sight of my son's execution? Or sparing me from discovering some even more horrible fate that had already overtaken Meto? My weary imagination spun out of control.

"I'll tell you what," said Vitruvius brightly. "I saw a couple of folding chairs over by Trebonius's tent. I'll fetch them. We can sit here together and wait for the sun to come up. Reminisce about the siege of Brundisium, or whatever. You must have fresh news from Rome. I can't imagine what it's like there now, with Caesar's friend Marc Antony left in charge. One big orgy, I should think. Stay here."

He went off to fetch the chairs and quickly returned, with a couple of blankets as well.

We talked about Caesar's chances of putting a quick end to his enemies in Spain; about Pompey's prospects of raising a formidable force in the East to challenge Caesar; about Antony's reputation for drunken carousing. Sober or not, Antony had maintained strict order. The mood in Rome, I assured Vitruvius, was far from orgiastic. Stunned by the tumult of the last few months and fearful of the future, the city held its breath and walked on tiptoes with round eyes, like a virgin in the wildwoods.

We talked about the famous Roman exiles who had taken up residence in Massilia over the years. Gaius Verres was the most notorious; as governor of Sicily his rapaciousness had reached such extremes that Cicero had successfully prosecuted him for malfeasance and sent Verres packing for Massilia, taking a fortune in plunder with him. The reactionary gang-leader Milo had fled to Massilia after being found guilty of murdering the radical gang-leader Clodius; what would be his fate if Caesar took the city? There were scores of such exiles in Massilia, including men who had been convicted of various political crimes under Pompey's campaign to "clean up" the Senate; some were no doubt as crooked as crone's teeth, but others had simply made the mistake of crossing Pompey and the anti-Caesarians who had ruled the Senate in recent years. Inside the walls of Massilia, there must even be some old followers of Catilina, rebels who had chosen flight and exile over falling in battle beside their leader.

I stared at the walls of Massilia and the dark, hulking behemoth of the city beyond and wondered if Verres and Milo and all the rest were sleeping. What was it like to be a Roman exile in Massilia with Rome's new master knocking at the gates? Some must be quivering with dread, others with jubilation.