CLARKSVILLE -- The way is dark. The way is winding. The way is way too small.
''What size suit do you wear?" Chris Taylor asked, his body halfway into an opening perhaps 18 inches high, and no more than 2 1/2 feet wide. ''Forty-two, you should be OK." His voice is muffled. ''Forty-four, 46, you might be in trouble."
Without waiting for a response, Taylor squirmed deeper, twisting his body from side to side like a cold-blooded thing. ''Wonder if I'll fit," he mused. ''I gained 10 pounds this winter . . ."
His words trail away. Soon, only the bottoms of his boots are visible, then nothing.
Taylor is the trip coordinator for the Boston Grotto, the local chapter of the National Speleological Society. The rest of the caving party -- Tom Kinsky, Katharine Lea, Leander and Elsbeth Nichols -- has wisely chosen the better-known, roomier Ward Entrance that leads directly to the Big Room.
But Taylor, 54, has persuaded a first-time caver to attempt the Thook Entrance: an unmarked, chimney-sized hole in the earth. Entering here, a visitor must suffer a breath-stealing crush through the Chest Compressor.
Like the world above, subterranean places have logical names. The Compressor's overhead clearance is too low even for on-hands-and-knees. Shoving a fanny pack in front of him, a caver, dressed in blue coveralls, must grunt and curse and pull himself inchworm fashion for some 50 feet through profound darkness lighted only by the beam from a headlamp.
Oh-oh-oh, the novice panics. Internal demons clamor. It's OK, it's OK . . . No. No-no-not-FITTING. Oh-my-god-I'm-going-to-die-down-here! . . . Must -- keep -- head [clunk!] -- low.
Tons of mud-smeared rock oppress from above. The passage coils deeper below.
Taylor shouts out an expletive. Then, ''OK, I figured it out. For this next stretch, you gotta turn your body sideways like this, then . . ."
Hello, down-and-dirty, do-it-yourself caving.
This is not some tourist trip to nearby Howe Caverns off Interstate 88 or overrun Carlsbad out in New Mexico. Commercial caves have stairs, paved walkways, and garish lighting. They are family-oriented natural attractions.
Ward-Gregory Cave, part of the vast karst (an area of dissolved, Onondaga limestone) that lurks under parts of Schoharie and Albany counties, is not meant for amateurs. When exploring solutional caves, those formed by acidic groundwater, the going is slow and muddy and wet. Kneepads are indispensable. Brains, too. Claustrophobia-provoked freak-outs are expected. There is no gift shop.
''It's not a clean sport," Tom Kinsky, another Boston Grotto officer, had said earlier.
Another thing: Don't call it ''spelunking." Cavers hate that.
Formed along a fault zone, with three entrances and about 4,800 feet of mostly straight passageways, Ward-Gregory is probably the best-known and most visited wild cave in the Northeast. Unlike vertical caving, which requires rock-climbing skills, Ward-Gregory's terrain is mostly horizontal. It's an ideal get-your-feet-wet cave.
But the Boston Grotto and the Northeastern Cave Conservancy, the organization that owns and maintains Ward-Gregory, insist first-timers always enter properly equipped, with three light sources, accompanied by an experienced caver. Neither group is thrilled to see the cave get publicity. If you know where it is, you probably already know something about caving. Cavers are loath to reveal their caves' exact whereabouts.
''There are a lot of people that come there and some are not respectful of caving," Steve Stokowski, Boston Grotto chairman, said, recounting anecdotes about hooting, rock-throwing groups and drunk teenagers.
Caves are vandalized by souvenir-hunters. Hibernating bats are disturbed by headlamps. Even well-intentioned cavers, in volume, will degrade formations: Fragile rimstone dams crumble under heavy boots; a stalactite gripped by thousands of hands wears down or snaps off. Even so, with Ward-Gregory, obfuscation is less about protecting the identity of an unknown cave than preventing the general public from entering the cave ill-equipped.
''Over the years we've had a lot of rescues at the cave," said Thom Engel, an NCC preserve manager. ''With all but one notable exception, [the rescued] had been doing something stupid, like going into the cave with a Mini Maglite, where the battery lasts an hour and you need two hours to get out."
A half-mile-long cave can be as lethal as a much longer one. Engel paints a scenario: You drop your lone lamp. The bulb shatters. You stumble around in the dark. Perhaps you break an ankle. You get cold and wet. Hypothermia sets in. You starve, you freeze. You don't make it out.
In 2001, Robert Svensson, a student at Rensselaer Polytechnic Institute, dived into the Lake Room's 10-foot-deep pool. The lake conceals a 40-by-20-inch opening leading to Pauley's Avenue and 1,200 feet of rarely seen passageway beyond.
'' 'Lake' is a misnomer," Taylor explained. ''Only a few people have done it, because it's too dangerous." Svensson got wedged in the underwater crawlway, his tank ran out, and he drowned. ''He only had a 20-minute pony bottle." Taylor shook his head.
By now, Taylor has led his guest past the Chest Compressor, through the constricting Pictograph Crawl to the comparably roomy, up to 15-foot-high, 40-foot-wide Perry Avenue. Depending on ceiling height, moving through this cavern is either a belly-slither, a crab-like crooked scramble, or a hunched-over duck waddle. Here, about 50 feet below the surface, it's possible to walk fully upright through the shin-high water of the underground stream. Taylor's padded jumpsuit and layers of wool clothing block the damp from seeping through to his skin.
Today he is caving old-school, with a carbide lamp. The technology is 19th-century simple: Water dripping from one sealed canister reacts with chunks of carbide in another, producing acetylene gas. Taylor flicks the flint. Out jets a brilliant, yellow-white flame from the fixture, which he screws to his helmet. ''I prefer the warm glow of carbide to the cool blue of electric light," he said.
Ahead is the Big Room, about the size of two school buses, and full of breakdown: massive chunks of fallen rock. The others have set up lunch. It is April Fool's Day, and the Boston Grotto is reviving an annual tradition, dating to at least 1987, of formal dining by candlelight. Kinsky, 42, brought a table. Leander Nichols, 54, dons a tuxedo, his wife Elsbeth, 50, stirs her pot of Swiss fondue. Lea, 36, slips into her sparkly evening gown. Then, Boy Scout Troop 117 from East Setauket, Long Island, marches through. The meal is incongruous, and silly, but the food and drink make good fuel.
''But you can't go No. 1 here," Kinsky reminds the group. ''[Go] outside."
With the meal cleaned up, four cavers hike to the Lake Room at the end of the Ward section, then double-back to Gregory, where tight squeezes filter out most of the masses. At the Corkscrew, Taylor scouts ahead to find the best route through.
''This one separates the men from the boys," Taylor cracked. ''The boys can make it and the men can't." He enters feet first. Halfway through, like a contortionist, he does a 180 and exits with his head.
Lea balks. ''I can't do it." Taylor convinces her to try, and after a little cajoling, she, too, masters what Kinsky calls ''reexperiencing the birth canal." Lea glows, thrilled she pushed herself to do it.
On the other side, past the Bathtub and a tubular, 20-foot chute straight out of a spy movie, the formations are better preserved: black, knobby protrusions called chert (deposits made of silica), scalloped wall ridges, and embedded in a tube of limestone from the Devonian era, 400-million-year-old fossils of crinoids and brachiopods.
''I've never seen these here before," Taylor said.
After five hours underground, a final challenge awaits at Brinley's Sump. A curtain of rock hangs above a pool. The only way through is to wade in neck-deep, 48-degree water, duck under the ledge and scramble to a dry passage. Leander Nichols waits at the other side.
One by one, the party takes its bath. Dripping, they read the pool namesake's graffiti, etched into the limestone. ''1839 E Brinley Amboy NJ."
From here, it should be easy.
''You know the way," said Taylor. ''You can lead us."
''I don't remember the way," replied Leander Nichols.
The cavers tromp through Lower and Upper Cook Avenues. The rooms grow in size.
''Look up," said Kinsky.
Headlamps reflect off the ceiling. Uncountable dots like flecks of fool's gold cling to the ceiling. They are actually calcite particles suspended in bubbles of water. To one caver, they glimmer like stars.
Breath, first stolen in the Chest Compressor, is taken away again. The way doesn't matter anymore.
Contact Ethan Gilsdorf, a freelance writer in Somerville, at email@example.com.