"The weight of the water pushes on the dam," he said. "If the wall is straight, only the strength of the wall holds it back. If it is curved, the water pushes the earth and rock into the sides."

"Lord?" the architect said, baffled.

Walker sheathed his sword and looked around. Don't underestimate them, he reminded himself. They built good roads for this era, and aqueducts, bridges, towers of great cyclopean blocks; they knew how to handle stone, in a solid rule-of-thumb, brute-force-and-massive-ignorance fashion.

The problem is that they've got a set of rote answers to known problems but no concept of calculating stresses and forces.

Ah, he thought after a moment, and cut a branch. "Here," he said, holding it straight between his palms. "Push downward."

Augewas did, and the green stick curved under his finger. "Now," Walker went on, "I will bend it upward like a bow." He did so. "Push again. See how it resists the push? Now put it between your own palms and I will push. Held straight, only the strength of the stick opposes my finger. Now bend it into an upward arch. Feel how the push goes against your hands when it is bent?"

"So… so the force of the water will push against the sides of the embankment, where it butts into those ledges of rock!" Augewas said, pointing. Another thought struck him. "And we will not need to build it so thick, to be just as strong!"

"Exactly. That will flood all this land here."

Augewas, a dark grizzled man, nodded brusquely. Enkhelyawon looked slightly shocked at the lack of formality, but Walker let it slide. He recognized the attitude; it was a professional focusing on his work, not somebody dissing the boss.

"That, yes," he said. "That will give you a head of water. But where do you wish to take it, lord?"

He waved toward the valley of the Eurotas. Clustered, flat-topped peasant huts of mud brick showed here and there amid grainfields and olive groves, occasionally the larger house of a telestai, a baron. On the edge of vision was the megaron-palace near the site of classical Sparta. Like that later city, it was unwalled, but for a different reason-the High King of Mycenae forbade stone defenses, as he did at Pylos and a few other places directly under his gaze.

"We might use some of it for irrigation, eventually," Walker said. "But come, I will show you what the first use will be."

He led them over to a trestle table of logs. On it stood a model three feet high. "These are my handfast men Cuddy and Bierman," he went on. "And this is a… replica in small… of what we will build below the dam."

It showed a wheel of timbers forty feet across, with a chute to bring the water to its top and spill onto the curved blades within. At Walker's nod, Bill Cuddy poured a small bucket of water into the pan at the top of the model, letting it run down a wooden chute. The wheel turned on its axle, and the cams on the shaft moved hammers, pumped a piston bellows, turned a small round grindstone.

Augewas looked on in fascination as Cuddy explained the operation of the machine with patient repetition, turning frequently to look at the dam site, visibly struggling to turn the model into an image in his mind.

"The first thing the water mill does," Walker went on, backtracking occasionally to explain when he had to use an English word with no Achaean equivalent, "will be to drive the bellows for the blast furnace."

"For the iron, lord?" Augewas said eagerly. He'd seen samples from the tons the Yare had carried, and these people knew about iron in the abstract-they bought small quantities through the Hittites for ornament or special uses. They just didn't know how to smelt it or work it properly yet. "There is ore, near here?"

Bierman put a sack of cracked rocks down on the table and spoke in slow, careful Achaean: "About sixty-five percent… that's six parts in ten, I mean… iron. Hematite ore-real nice, except I think there may be traces of nickel, maybe a little chrome."

"Besides the ore of iron," Walker said, "we need charcoal in large amounts and very pure, soft limestone for flux. We will need many hundreds of laborers, to bring those and all the other necessary things together. Metalworkers must be trained; I have a master ironsmith and a dozen men who have been learning from him. Then when we have the iron from the blast furnace, it must be further worked with heat and hammers-very heavy hammers…"

Enkhelyawon tossed his head in a purely Greek gesture. "The wannax has decreed that this must be so. Spend and spare not what is needed; I heard him say so, the royal word from the King's own lips."

Augewas nodded himself, more slowly, a beatific smile spreading over his lined face at the prospect of an unlimited cost-plus contract, or the Bronze Age equivalent. "That is a command worthy of a king indeed. One seldom heard in these sad times, when great lords clutch their bronze and silver hard and trade is so troubled. Then besides the dam, we must build channels for the water," he went on. "This furnace itself…"

"It will be of stone, shaped like a tower that tapers from the base to the top, but it must be lined with a special type of brick," Walker said. "My men are looking for it-fireclay, we call it. There must be ramps to the lip of the stack." He went on, pointing out details.

Augewas stood silent for a moment after he finished. "I see, lord," he said at last. "Then there are these buildings. And we must have roads, roads in the hill country here, to fetch the materials. Barracks and storehouses of food and other goods, for the workers. Houses for the masters and overseers. A great project, lord, one worthy of my skill. Here I will learn much, as well as do much."

Walker smiled. Great, he thought. An enthusiast. Now he could get back to Mycenae for a while and do some intensive politicking.

"Everything's a trade-off," Jared Cofflin said.

Martha made a noncommittal noise from behind him. "This one is an expensive trade-off," she noted.

Cofflin grunted in his turn and pushed harder on the pedals. The two-person tricycles were the transportation of choice for those who could get them, and he didn't feel easy commandeering a horse carriage now that Martha wasn't lugging around a nursing infant anymore.

Maybe they'd buy one in a year or two, when horses were cheaper. Of course, then I'd have to rent space in a stable, and it'd take forever to get the damned thing ready. Animals couldn't just be parked until you needed them.

They were moving out Hummock Pond Road, south and west of town. It was a bit eerie, having so many different landscapes in your mind's eye. The thick, tangled scrub that had covered the Island since long before he was born, then the frantic chopping and burning, and there were fields of grain and potatoes fertilized with ash and fish offal… and now changing again, to pasture and orchard.

Now and then they passed people at work, a farmer on a sulky-plow turning furrows as he rode behind two horses, wagons scattering fertilizer or pulverized oyster shells, long rows of harvest workers gathering late vegetables, a herd of close-sheared sheep flowing around the bicycle like lumpy white water as it was driven by two teenagers and an extremely happy collie. A wagon driven by a policeman went by with a dozen resentful-looking, hungover men in it; drunk-and-disorderly convictions, he thought, going out to work off a couple of days helping to mine Madaket Mall-the old landfill dump, which was full of irreplaceable stuff. He nodded and smiled to the peace officer. That was lousy work, worse than shoveling garbage in its way.

"Getting old for this," Cofflin puffed, glad of the excuse to stop when a hauler did, dropping off bales of coarse salt-marsh hay from the mainland.

"Not as old as you were the first year," Martha said, and he chuckled.

True enough. God, the way my thighs ached! He felt stronger now than he had the day of the Event, and he'd certainly lost the small pot that had been marring his lean frame.