Vitruvius told me more about the siege. The first major engagement had been a sea battle. A surprisingly small Massilian navy of seventeen ships had ventured out of the harbor. Caesar's twelve ships sailed from behind the islands to meet them. Massilians watched from the city walls, while Romans watched from the hill upon which we sat. "Not much of a navy," said Vitruvius, disparaging his own side. "Ships hastily thrown together with green wood, heavy in the water, manned by soldiers who'd never sailed before in their lives. They didn't even bother to try to outmaneuver the Massilians; they just rammed straight ahead, caught the enemy ships with grappling hooks, rushed on board, and fought hand-to-hand across the decks, as if they were attacking on dry land. The sea turned red with blood. You could see great patches of red from up here, bright crimson against the blue of the sea."

That battle went badly for the Massilians. Nine of their seventeen ships were sunk or captured; the rest fled back to the harbor. Only the powerful offshore wind, for which the southern coast of Gaul is famous, kept Caesar's ships from pursuing; with the wind against them, only experienced Massilian sailors were able to maneuver through the straits and into the harbor. But the battle confirmed the blockade. Massilia was cut off by both land and sea.

There might yet be another sea battle if Pompey managed to send naval reinforcements to the Massilians. But Vitruvius remained convinced that the conflict would be settled on land, not water, and sooner, not later. "Tomorrow," he whispered, as I drifted off to an uneasy slumber beneath my blanket, too weary despite my worries to stay awake a moment longer.

IV

In the hour before sunrise, I gradually woke. Night and sleep receded in imperceptible stages. A hazy, dreamlike vision infiltrated the waking world. Out of the grayness, the arena of battle described by Vitruvius emerged before me.

Huddled in my folding chair with the blanket wrapped around me and over my head like a cowl, I saw the milky white walls of Massilia tinged with a faint pink blush by the growing predawn light. The black behemoth beyond acquired depth and definition, became a ridge of hills with houses crowded close together along the slopes and temples and citadels crowning the hilltops. The sea beyond turned from black obsidian to blue lead. The islands outside the harbor acquired solidity and dimension.

In the valley below me, the contravallation that circled Massilia cut like a scar across the trampled earth. The embankment that Vitruvius had described rose like a great dam across the valley, and the movable siege tower loomed below us. I saw no sign of the tunnels Vitruvius had talked about, but toward my left, at a corner where the landward wall bent sharply back to run along the harbor, I saw the massive towers that flanked the main gate into Massilia. Somewhere in that vicinity, Caesar's men intended to dig their way to daylight.

Slowly but surely-as slowly and surely as these images manifested out of darkness-I came to a decision.

It seemed to me that in my younger days I had always been methodical and cautious, slow to take any step that might be irrevocable, fearful of making a mistake that might lead to the worst possible outcome. How ironic that in my years of hard-earned wisdom I should become a creature of impulse, a taker of wild risks. Perhaps it was wisdom after all for a man to turn his back on fear and doubt and trust to the gods to keep him alive.

"Vitruvius?" I said.

He stirred in his chair, blinked, and cleared his throat. "Yes, Gordianus?"

"Where does the tunnel begin-the one that's to break through inside the city today?"

He cleared his throat again. He yawned. "Over to the left. Do you see that stand of oak trees down there, tucked in a hollow that curves into the hillside? Actually, you can just barely see the treetops. That's where the entrance of the tunnel is, almost directly across from the main gate but still hidden from the city walls. The sappers are probably down there already, relaying digging equipment, rechecking measurements. The soldiers who'll take part in the attack will start gathering in about an hour."

I nodded. "How will they be equipped?"

"Short swords, helmets, light armor. Nothing too heavy. They've got to stay light on their feet, as unencumbered as possible. We don't want them tripping or stabbing each other as they scramble through the tunnel, or weighed down with too much equipment when they need to climb out."

"Are they all from a particular cohort?"

"No. They're special duty volunteers culled from several cohorts. Not every man's fit for such a mission. You can't effectively train a man not to be afraid of the dark or not to panic in a tight, enclosed space. Put some men in a tunnel and it doesn't matter how brave they are, they wet themselves the instant they lose sight of daylight around the first bend. You don't want to be standing next to such a fellow in a crisis. Sappers thrive in tunnels, of course, but sappers are diggers, not fighters. So you've got to have fighting men who aren't afraid to step on a few earthworms. The volunteers who'll make the attack have been doing tunnel drills over the last few days. How to carry a lighted taper so it doesn't go out, how not to stampede your comrades if the tunnel goes black, memorizing signals to advance and retreat, and so on."

"Sounds complicated."

Vitruvius snorted. "Hardly. These fellows aren't engineers. They're simple men. They just needed a bit of drilling so they won't trip over their own feet in a tight spot."

I nodded thoughtfully. "I suppose any reasonably bright fellow could pick up what to do on the spot."

"Certainly. Any fool could. And if something did go horribly wrong, he'd die just as quickly as the ones who've been specially trained for the mission." He snuggled under his blanket, closed his eyes, and sighed.

A red glimmer appeared along the jagged horizon to the east. I shrugged off my blanket and told Vitruvius he would have to watch the sunrise alone. He didn't answer. I retreated to the sound of gentle snoring.

In the officers' tent I managed to wake Davus and pull him from his bed without rousing the others. Half-asleep and confused, he nodded as I explained to him my intention.

From Meto I knew how Caesar arranged his camps and where stores of surplus equipment might be found. The tent I was looking for was just behind that of Trebonius, and unguarded. What penalty would the commander deem appropriate for two outsiders caught stealing weapons during a siege? I tried not to think about that as we searched in the dim light among dented helmets, nicked swords, and mismatched greaves.

"This one fits perfectly, father-in-law. And I can't find any damage at all."

I looked up to see Davus trying on a helmet. I shook my head. "No, Davus, you misunderstood. My fault for explaining while you were still half-asleep. I will be going through the tunnel, not you."

"But I'm coming with you, of course."

"There's no need. If Vitruvius is correct, the city will be open in a matter of hours. We can meet up again tomorrow, perhaps even tonight."

"And if the engineer is wrong? You know what Meto says: Things never go exactly the way they expect in a battle."

I ran my fingertip along a dull, rusty sword blade. "Davus, do you remember the scene the day before we left Rome? Your wife-my daughter-was very, very upset."

"No more than your wife! Bethesda was frantic. Those curses she uttered made my hair stand on end, and I don't even know Egyptian."

"Yes, Diana and Bethesda were both distraught. But the night before we left, I made my peace with Bethesda. She understood why I had to come here, why I couldn't sit idly in Rome wondering about Meto, not knowing for certain if he was alive or dead. Diana was another matter."