The road, from which we ought never to have strayed, was splendid in engineering and surface, and we winged down to earth in a flight from the clouds.  Ice and snow were left behind on the heights, and the Aigle gaily careered down the slopes like a wild thing released from a weary bondage.  As we whirled earthwards, embankments and railway bridges showed here and there by our side, but we lost all such traces of feverish modern civilization as we swept into the dusky hollow at the bottom of which Florac lay, like a sunken town engulfed by a dark lake.

We did not pause in the curiously picturesque place, which looked no more than a village, with its gray-brown houses and gray brown shadows huddled confusedly together.  Probably it looked much the same when the Camisards used to hide themselves and their gunpowder in caves near by; and certainly scarce a stone or brick had been added or removed since Stevenson’s eyes saw the town, and his pen wrote of it, as he turned away there from the Tarn region, instead of being the first Englishman to explore it.  And what a wild region it looked as we and the Aigle were swallowed up in the yawning mouth of the gorge!

In an every-day world, above and outside, no doubt it was sunset, as on other evenings which we had known and might know again; but this hidden, underground country had no place in an every-day world.  It seemed almost as if my brother and I (I can’t count the Turnours, for they were so unsuitable that they temporarily ceased to exist for us) were explorers arriving in an air-ship, unannounced, upon the planet Mars.

The moon, a glinting silver shield, shimmered pale through ragged red clouds like torn and blood-stained flags; and the walls of the gorge into which we penetrated, bleakly glittering here and there where the moon touched a vein of mica, were the many-windowed castles of the Martians, who did not yet know that they had visitors from another world.

There were fantastic villages, too, whose builders and inhabitants must have drawn their architectural inspiration from strange mountain forms and groupings, after the fashion of those small animals who defend themselves by looking as much as possible like their surroundings.  And if by some mistake we hadn’t landed on Mars, we were in gnome-land, wherever that might be.

There was no ordinary twilight here.  The brown-gray of rocks and wild rock-villages was flushed with red and shadowed with purple; but as the moon drank up the ruddy draught of sunset, the landscape crouched and hunched its shoulders into shapes ever more extraordinary.  The white light spilled down from the tilted crescent like silver rain, and bleached the few pink peach-blossoms, which bloomed timidly under the shelter of snow-mountains, to the pallor of fluttering night-moths, throwing out their clusters in sharp contrast against dark rocks.  The River Tarn, gliding onward through the gorge toward the Garonne, was scaled with steel on its emerald