After going halfway up an incline and then coming down again, he stopped and turned slowly in a full circle. Either his eyes were getting used to it, or dawn was close now, in which case they were almost out of time. The others had halted behind him. He could hear their heavy breathing. Here was another story for them to take back to Misenum—how their new young aquarius had dragged them from their beds and marched them into the hills in the middle of the night, and all on a fool's errand. There was a taste of ash in his mouth.

"Are we lost, pretty boy?"

Corax's mocking voice again.

He made the mistake of rising to the bait: "I'm looking for a rock."

This time they did not even try to hide their laughter.

"He's running around like a mouse in a pisspot!"

"I know it's here somewhere. I marked it with chalk."

More laughter—and at that he wheeled on them: the squat and broad-shouldered Corax; Becco, the long-nose, who was a plasterer; the chubby one, Musa, whose skill was laying bricks; and the two slaves, Polites and Corvinus. Even their indistinct shapes seemed to mock him. "Laugh. Good. But I promise you this: either we find it before dawn or we shall all be back here tomorrow night. Including you, Gavius Corax. Only next time make sure you're sober."

Silence. Then Corax spat and took a half step forward and the engineer braced himself for a fight. They had been building up to this for three days now, ever since he had arrived in Misenum. Not an hour had passed without Corax trying to undermine him in front of the men.

And if we fight, thought the engineer, he will win—it's five against one—and they will throw my body over the cliff and say I slipped in the darkness. But how will that go down in Rome—if a second aquarius of the Aqua Augusta is lost in less than a fortnight?

For a long instant they faced each other, no more than a pace between them, so close that the engineer could smell the stale wine on the older man's breath. But then one of the others—it was Becco—gave an excited shout and pointed.

Just visible behind Corax's shoulder was a rock, marked neatly in its center by a thick white cross.

Attilius was the engineer's name—Marcus Attilius Primus, to lay it out in full, but plain Attilius would have satisfied him. A practical man, he had never had much time for all these fancy handles his fellow countrymen went in for. ("Lupus," "Panthera," "Pulcher"—"Wolf," "Leopard," "Beauty"—who in hell did they think they were kidding?) Besides, what name was more honorable in the history of his profession than that of the gens Attilia, aqueduct engineers for four generations? His great-grandfather had been recruited by Marcus Agrippa from the ballista section of Legion XII "Fulminata" and set to work building Rome's Aqua Julia. His grandfather had planned the Anio Novus. His father had completed the Aqua Claudia, bringing her into the Esquiline Hill over seven miles of arches, and laying her, on the day of her dedication, like a silver carpet at the feet of the emperor. Now he, at twenty-seven, had been sent south to Campania and given command of the Aqua Augusta.

A dynasty built on water!

He squinted into the darkness. Oh, but she was a mighty piece of work, the Augusta—one of the greatest feats of engineering ever accomplished. It was going to be an honor to command her. Somewhere far out there, on the opposite side of the bay, high in the pine-forested mountains of the Apenninus, the aqueduct captured the springs of Serinus and bore the water westward—channeled it along sinuous underground passages, carried it over ravines on top of tiered arcades, forced it across valleys through massive siphons—all the way down to the plains of Campania, then around the far side of Mount Vesuvius, then south to the coast at Neapolis, and finally along the spine of the Misenum peninsula to the dusty naval town, a distance of some sixty miles, with a mean drop along her entire length of just two inches every one hundred yards. She was the longest aqueduct in the world, longer even than the great aqueducts of Rome and far more complex, for whereas her sisters in the north fed one city only, the Augusta's serpentine conduit—the matrix, as they called it: the motherline—suckled no fewer than nine towns around the Bay of Neapolis: Pompeii first, at the end of a long spur, then Nola, Acerrae, Atella, Neapolis, Puteoli, Cumae, Baiae, and finally Misenum.

Excerpted from Pompeii by Robert Harris. Copyright © 2003 by Robert Harris. Excerpted by permission of Random House, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.