Le Cagot’s laughter echoed, filling the cave. “Ola! What if it suddenly gets wider, Niko? Maybe you had better lock up there and let me use you like a bridge. That way at least one of us would make it!” And he laughed again.

Mercifully, it didn’t get wider. Once past the knob, the cut narrowed, and the roof rose overhead to a height beyond the beam of Hel’s lamp. He was able to push himself back to the interrupted ledge. He continued to inch along it, still curving to the left. His heart sank when his lamp revealed ahead that the diaclase through which they had been moving came to an abrupt end at an infall of boulders, under which the river gurgled and disappeared.

When he got to the base of the infall raillère and looked around, he could see that he was at the bottom of a great wedge only a couple of meters wide where he stood, but extending up beyond the throw of his light. He rested for a moment, then began a corner climb at the angle of the diaclase and the blocking wall of rubble. Foot– and handholds were many and easy, but the rock was rotten and friable, and each stance had to be tested carefully, each hold tugged to make sure it would not come away in his hand. When he climbed a slow, patient thirty meters, he wriggled into a gap between two giant boulders wedged against one another. Then he was on a flat ledge from which he could see nothing in front or to the sides. He clapped his hands once and listened. The echo was late, hollow, and repeated. He was at the mouth of a big cave.

His return to the knob was rapid; he rappelled down the infall clog on a doubled line which he left in place for their ascent. From his side of the knob he called to Le Cagot, who had retreated a distance back down the tunnel to a narrow place where he could lock himself into a butt-and-heels stance and find some relief from the quivering fatigue of his half-squatting posture.

Le Cagot came back to the knob. “So? Is it a go?”

“There’s a big hole.”

“Fantastic!”

The packs were negotiated on a line around the knob, then Le Cagot repeated Hel’s chimney traverse around that tight bit, complaining bitterly all the while and cursing the knob by the Trumpeting Balls of Joshua and the Two Inhospitable Balls of the Innkeeper.

Because Hel had left a line in place and had cleared out much of the rotten rock, the climb back up the scree clog was not difficult. When they were together on the flat slab just after the crawl between two counterbalanced boulders that was later to be known as the Keyhole, Le Cagot struck off a magnesium flare, and the stygian chaos of that great cavern was seen for the first time in the numberless millennia of its existence.

“By the Burning Balls of the Bush,” Le Cagot said in an awed hush. “A climbing cave!”

It was an ugly sight, but sublime. The raw crucible of creation that was this “climbing” cave muted the egos of these two humanoid insects not quite two meters tall standing on their little flake of stone suspended between the floor of the cave a hundred meters below and the cracked and rotten dome more than a hundred meters above. Most caves feel serene and eternal, but climbing caves are terrible in their organic chaos. Everything here was jagged and fresh; the floor was lost far below in layers of house-size boulders and rubble; and the roof was scarred with fresh infalls. This was a cavern in the throes of creation, an adolescent cave, awkward and unreliable, still in the process of “climbing,” its floor rising from infall and rubble as its roof regularly collapsed. It might soon (twenty thousand years, fifty thousand years) stabilize and become an ordinary cave. Or it might continue to climb up the path of its fractures and faults until it reached the surface, forming in its final infall the funnel-shaped indentation of the classic “dry” gouffre. Of course, the youth and instability of the cave was relative and had to be considered in geological time. The “fresh” scars on the roof could be as young as three years old, or as old as a hundred.

The flare fizzled out, and it was some time before they got their cave eyes back sufficiently to see by the dim light of their helmet lamps. In the spot-dancing black, Hel heard Le Cagot say, “I baptize this cave and christen it. It shall be called Le Cagot Cave!”

From the splattering sound, Hel knew Le Cagot was not wasting water on the baptism. “Won’t that be confusing?” he asked.

“What do you mean?”

“The first cave has the same name.”

“Hm-m-m. That’s true. Well, then, I christen this place Le Cagot’s Chaos! How’s that?”

“Fine.”

“But I haven’t forgotten your contribution to this find, Niko. I have decided to name that nasty outcropping back there—the one we had to traverse—Hel’s Knob. How’s that?”

“I couldn’t ask for more.”

“True. Shall we go on?”

“As soon as I catch up.” Hel knelt over his notebook and compass, and in the light of his helmet lamp scratched down estimates of distance and direction, as he had every hundred or so meters since they left base camp at the rubble heap. After replacing everything in its waterproof packet, he said, “All right. Let’s go.”

Moving cautiously from boulder to boulder, squeezing between cracks and joints, picking their way around the shoulders of massive, toppling rocks the size of barns, they began to cross the Chaos. The Ariadne’s String of the underground river was lost to them beneath layers upon layers of boulders, seeping, winding, bifurcating and rejoining, weaving its thousand threads along the schist floor far below. The recentness of the infalls and the absence of weather erosion that so quickly tames features on the surface combined to produce an insane jumble of precariously balanced slabs and boulders, the crazy canting of which seemed to refute gravity and create a carnival fun house effect in which water appears to run up hill, and what looks level is dangerously slanted. Balance had to be maintained by feel, not by eye, and they had to move by compass because their sense of direction bad been mutilated by their twisting path through the vertigo madness of the Chaos. The problems of pathfinding were quite the opposite of those posed by wandering over a featureless moonscape. It was the confusing abundance of salient features that overloaded and cloyed the memory. And the vast black void overhead pressed down on their subconsciouses, oppressed by that scarred, unseen dome pregnant with infall, one-ten-thousandth part of which could crush them like ants.

Some two hours and five hundred meters later they had crossed enough of the Chaos to be able to see the far end of the cave where the roof sloped down to join the tangle of jagged young fall stone. During the past half-hour, a sound had grown around them, emerging so slowly out of the background ambience of gurgle and hiss far below that they didn’t notice it until they stopped to rest and chart their progress. The thousand strands of the stream below were weaving tighter and tighter together, and the noise that filled the cavern was compounded of a full range of notes from thin cymbal hiss to basso tympany. It was a waterfall, a big waterfall somewhere behind that meeting of roof and rubble that seemed to block off the cave.

For more than an hour, they picked back and forth along the rubble wall, squeezing into crevices and triangular tents formed of slabs weighing tons, but they could find no way through the tangle. There were no boulders at this newer end of the Chaos, only raw young slab, many of which were the size of village frontons, some standing on end, some flat, some tilted at unlikely angles, some jetting out over voids for three-fourths of their length, held up by the cantilevering weight of another slab. And all the while, the rich roar of the waterfall beyond this infall lured them to find a way through.

“Let’s rest and collect ourselves!” Le Cagot shouted over the noise, as he sat on a small fragment of slab, tugged off his pack, and pawed around inside for a meal of hardtack, cheese, and xoritzo. “Aren’t you hungry?”