Perhaps if I describe it as I first saw it… through a fever haze, of course, but I was not delirious, although it might sound that way.

Caroline, be patient. I fear your incredulity.

Picture us, a ragged band of men in animal furs, some walking, some limping, some dragged on harnesses, starved and freezing as we cross another snowy ridge and peer down into yet another wilderness valley… Diggs with his ruined arm, Sullivan limping pitifully, me on a sledge because I still could not walk any significant distance. According to Farr I was suffering the effect of the insect venom on my liver. I was feverish and yellow and — well, I won’t go into detail.

Another alpine valley, but this one was different. Tom Compton had scouted it out.

It was a broad river valley, cut from stony soil and populated with dour, spiky mosque trees. From my place on the sledge, wrapped in furs, that was all I saw at first: the slope of the valley and its dark vegetation. But the rest of the party fell quickly silent, and I raised myself up to see what had alarmed them, and it was the single thing I had least expected to see in this desolate land.

A city!

Or the ruin of a city. It was a vast mosaic through which a river had run riot, visibly aged but obviously the work of intelligent builders. Even at this distance it was apparent the architects were long gone. Nothing walked this city’s relentlessly parallel streets. The buildings still intact were iron-gray boxes hewn from stone, softened by mist and time. And the city was large, Caroline, large beyond believing — a ruin that could have contained all of Boston and a couple of counties more.

For all its apparent age, the city’s outlying structures were more or less complete and handily available. This ruin promised everything we had despaired of finding: shelter for ourselves and our animals, a supply of fresh water, and (given the wooded hills and evidence of nearby snake herds) plentiful game. Tom Compton had scouted the city and environs and thought we could winter here. He warned us that the city was an uninhabited ruin, that we would have to work hard to keep ourselves warm in its drafty warrens, even with plentiful firewood. But since we had pictured ourselves dying in our snakeskin tents — or simply frozen to death in some Alpine pass — even this grim prospect seemed the gift of a benevolent God.

Of course the city raised countless questions. How had it come to exist, in a land void of human habitation, and what had happened to its builders? Were its builders even human, or some novel Darwinian race? But we were too exhausted to debate the ruin’s provenance or meaning. Only Preston Finch hesitated before descending the slope of the valley, and I don’t know what he feared; he hadn’t spoken aloud for day’s.

The prospect of shelter buoyed our spirits. We collected mosque and sage-pine windfall along the way, and before the stars began to shine in the wintry sky we had a fire roaring, casting fitful light among the colossal stones of the Nameless City.

Dear Caroline: I have not been as faithful in keeping this journal as I would have liked. Events are pressing.

There hasn’t been any new disaster — don’t worry — only the ongoing disaster of our isolation and the demands of the primitive life.

We live like Red Indians, in order to live at all. My fever has passed (for good, I hope) and my poisoned leg has regained its sensation and even some strength. I can walk a fair distance with only a stick for support and I have begun to accompany Tom Compton and Avery Keck on their hunting expeditions, though I’m still confined to the broad sweep of the valley. By spring I should have no trouble keeping up with the expedition when we finally make for Lake Constance and home.

For hunting we bundle ourselves in furs and hide boots. Our clothes are stitched with bone needles, the rags of our civilized clothing salvaged for thread. We have two rifles and even some ammunition, but most of our hunting is by bow or knife. Tom made the bows and shafts from local wood and bone, and he is still our only marksman. A rifle shot, he points out, could attract unwelcome attention, and the bullets might be needed on the journey home. I doubt the Partisans are anywhere nearby. Winter must hinder them as much as it hinders us. But several of us have experienced the sense of being watched from time to time.

We have captured a few fur snakes and corralled them in a ruined foundation with a half-roof for shelter. Sullivan looks after them and makes sure they have enough forage and water. He has switched from botany to animal husbandry, at least for the duration.

I’ve grown closer to Sullivan, perhaps because our parallel injuries (my leg, his hip) kept us confined together for some weeks. Often we’re left alone with Diggs or Preston Finch. Finch remains nearly wordless, though he helps with the physical labor. Sullivan, by contrast, talks to me freely, and I almost as freely to him. You might be wary of his atheism, Caroline, but it’s a principled atheism, if that makes any sense.

Last night we were assigned the late watch, a plush duty if you don’t mind the hours. We kept the fire burning and swapped stories, as usual, until we heard a commotion from the stables, as we call the semi-collapsed structure where the animals are kept. So we donned our furs and limped into the frigid night to investigate.

Snow had been falling all afternoon, and Sullivan’s torch cast a flickering glow across a boulevard of unsullied white. With its broken stones and fractured walls cloaked in snow the City seems only temporarily vacated. The buildings are identical, though in various stages of decay, and identically made, of huge bricks cut from raw granite and set in place without benefit of mortar. The bricks or blocks are perfectly square, about ten feet on a side. The buildings themselves are identically square and arranged in squares of four, as if by a meticulous but unimaginative child.

The doorways may once have possessed wooden doors, but if they ever existed they have long since rotted and weathered away. The openings are about twice as high as a man’s head and several times wider than his girth, but this, Sullivan points out, tells us virtually nothing of the original inhabitants — the doors of cathedrals are larger than the doors of sod huts, but the men who pass through them are the same. Nevertheless, the impression lingers of some squat, gigantic race, antediluvian, pre-Adamic.

We had put up a crude mosquewood fence to keep our twelve captive snakes corralled in their ruin. Usually they’re fairly quiet, barring the usual belching and mewling. Tonight the noise was nearly continuous, a collective moan, and we tracked it under the half-fallen stone eaves, where one of our herd was giving birth.

Or rather (we saw as we came closer) it was laying eggs. The eggs emerged from the beast’s pendulous abdomen in glittering clusters, each egg about the size of a softball, until a gelatinous mass of them lay steaming in a mound of windblown snow.

I looked at Sullivan. “The eggs will freeze in this weather. If we build a fire—”

Sullivan shook his head. “Nature must have made a provision,” he whispered. “If not, we’re too ignorant to help. Stand back, Guilford. Give them room.”

And he was right. Nature had made a provision, if an awkward one. When the female finished dropping her eggs a second animal, perhaps the male parent, approached the pearlescent mass and in a singular motion of its six limbs managed to scoop the eggs from the snow into pouches arrayed along its belly… there, presumably, to incubate until the hatchlings could survive on their own.

The moaning and barking finally relented, and the herd went back about its business.

We fled to the warmth of our own shelter. We had taken over two immense rooms in one of the less exposed buildings, partitioned and sealed them from the weather with snakeskins and made an insulating floor of dried rushes. The effect was cheerful, if only by comparison with the frigid outer dark.