“The missionaries of the Moravian Church,” he began, “established a foothold in Greece in 1737. It wasn’t long afterward, as evangelical history goes, that they pushed east into Turkey, then southeast into what is now Syria and Iraq.

“Among the more intrepid of them was Johann Durchfall, who, after much hardship and stormy weather, stumbled, on Whitsuntide 1762, onto a land the ancient Romans had abandoned sixteen hundred years earlier after a decade of unsuccessful colonization. They had called it Putoria; territorially it’s what we know today as Assama.

“Durchfall was a man of heroic design, with a spirit for daring as well as righteousness—something of an adventurer. He was other things as well—he had to be to survive. An accomplished carpenter, with a rudimentary knowledge of eighteenth-century medicine, which didn’t help him much—or perhaps it did—for not unlike Martin Luther he suffered from some gastrointestinal malady. Perhaps it was his interest in carpentry that provided his basic enthusiasm for Putoria, for what he found there was for him infinitely more fascinating than what he’d gone to do. In his journals he speaks of his ‘divine calling,’ of the joy of ‘spreading the Word of the Kingdom’ by one as ‘humble and obscure’ as himself, of his fervent hope that the rude and barbarous Putorians ‘would fall like ripe fruit before the gentle winds of the Gospel.’ He also delighted in being what evangelists had to be—farmer, brickmaker, a builder of houses and churches for his converts as well as himself.

“But he soon discovered that none of these attributes was of any use in Putoria. His parishioners, if such they could be called, repelled every aspect of the culture he tried to introduce by the simplest and most effective countermeasure: they ignored him. Soon he turned, not too reluctantly one would guess, to that element of Putorian life which interested him most: it is to the architecture that he devotes most of his writings. And of course it was the architecture that appealed to me, on that day when as a curiosity his journals appeared on my desk in Chicago.

“The text was astonishing, with vivid descriptions, originally in a terse, clear German, and clean three-dimensional drawings of structures as high as ten stories (and this in 1763) in a domed and gracefully rounded style as neat and balanced as a beehive.”

He paused again, knocking back his fourth martini. “And all of them,” he said in a peculiarly hushed voice, “fashioned not of brick and mortar, not of wood and stone but of mud and straw and human feces and…”

“I’m not quite clear. You’re talking excrement?”

“I’m talking human feces,” he repeated, “and one other ingredient.”

“Why excrement?”