"That's exactly what I thought you'd say," Ware told him, "and it sounds very noble, but it doesn't bear much relation to reality. Truth is, we interfere every time we come into contact with a local."

"Nonsense!" Crouzet snapped, and that was one of the milder reactions. Coordinator Chunder Sen, a devout Hindu, could not have looked more pained if he had suddenly discovered he'd been eating beef the last six weeks.

Ware did not mind. He felt filled with a sudden crazy confidence, like a gambler who knows the next card will make his straight, the next roll will be a seven. "It isn't nonsense," he insisted. "The physicists have known for a couple of thousand years that the act of observation affects what's being observed."

"Don't throw old Heisenberg at us out of context," said Moshe Sharett, the chief engineer. "He's only relevant at the atomic level. For large-scale phenomena, the observer effect is negligible."

"Who says Helmand's a large-scale phenomenon? Fifteen thousand people or so strikes me as being awfully different from the sextillions of atoms chemists and physicists play with."

Sharett scratched at an ear. Several other people frowned thoughtfully. Julian Crouzet, though, said, "I defy you to show me how walking through the streets of Helmand could twist the culture out of shape."

"Even that might. Suppose we bumped into someone and made him late for an important meeting, so a decision was taken that he would have changed if he'd been there. But walking about isn't all we do, you know. Remember that scrawny vendor we bought wine from? The grain we gave him could well have kept him and his whole family from starving. We might have changed a thousand years of bloodlines if a child that would have died grows up to breed."