Roberto's gentle brown eyes register a twinge of concern. Following his gaze, I see my husband, Paul, snapping a photo of an oak tree. Innocent enough, except this isn't just any oak tree. It is Roberto's secret hunting ground for white truffles, a knobby little fungus that can fetch more than $5,000 a pound at retail.

We'd made reservations at a farmhouse inn last October, near the tiny village of Murazzano in Italy's Piemonte region. The owner, Silvana Faggio, e-mailed us asking, "Can you say to me if you want to eat a dinner? Do you want a trouffle?" Trouffle, truffle, truffe, tartufi -- however you spell it, the answer was "yes." Paul and I are fans of the pungent subterranean delicacy.

Since it sounded as if Silvana had a local truffle connection, I wrote back asking if it would be possible to participate in a truffle hunt. So here we are, slogging through the damp countryside with truffle hunter Roberto Bovetti, his truffle dog, Gaia, and Silvana's gracious, English-speaking husband, Gianni Galli, who has offered to accompany us as translator.

A proper truffle hunt, it seems, must begin with a nip of grappa, high-octane liquor that fortifies the blood against chilly fall air. Roberto invited us into his family home, past three or four truffle dogs tethered in the farmhouse courtyard, yapping to go fetch some fungus. He set out bottles of flavored grappa (cherry, juniper) on the kitchen table and we toasted to a successful hunt.

Through Gianni, we learn that Roberto is 30 and that he works part time at a factory. He has dark, shoulder-length hair and a full beard. It would be easy to mistake him for Jesus of the Church of Truffles. He's a bit bewildered and flattered that foreigners would want to go poking around the countryside with him. "I have never had guests on a truffle hunt," he says.

Silvana has spent the morning phoning neighbors to borrow knee-length rubber boots for us. Now, in the misty late afternoon, the footgear makes me feel like a local, ready to muck undaunted across muddy fields and dank forests. Roberto has a scarf wound around his neck and sports a knit cap. His jacket and field vest have plenty of pockets, most to stash truffles, but one with treats to reward Gaia when she makes a find.

We cross the country road in front of Roberto's house and scramble down a scrubby embankment to a hazelnut orchard. Roberto tells us that truffles particularly like to grow in the soil around hazelnut, chestnut and oak trees. We are foraging through tartufaia, truffle lands.

Gaia, who looks vaguely poodle-esque, starts sniffing and scurrying in circles. Soon her shaggy, pinkish-tan hair is wet and streaked with mud. Roberto carries a cane, and I learn that it's not just a jaunty truffle-hunter prop but a tool that he uses to suggest spots where Gaia might search. He keeps up nonstop Italian patter, like a sotto-voce cheerleader, encouraging the dog and telling her where to look: "Here, here, look here, what about here, good girl, over here now." Roberto knows the areas where truffles have been found before -- knowledge handed down from his uncle -- but only Gaia can pinpoint their location.

After about five minutes of searching, Gaia suddenly scratches the dirt with her two front paws, sticks her nose in the hole and takes a big, unladylike snuffle. Roberto grabs her and pulls her back from the little indentation. "You have to stop them, because if they dig down to the truffle, they might eat it," he says. Roberto takes out an eight-inch tool, rather like a miniature hoe, and carefully carves the dirt away from what turns out to be a black truffle the size of a walnut. He wraps it in a square of paper and tucks it into a pocket.

Then Roberto turns back to the hole and scoops up some loamy, black earth. "Smell it," he says. We take a puzzled sniff and discover that even the earth reeks of truffle. It's a musky, sultry, decadent, decidedly sexual scent. "They only give off this aroma when they are ripe," he tells us, "So the dogs only find them when they are ready." He carefully replaces the dirt and layer of dead leaves where the truffle was extracted. Any evidence might tip off other truffle hunters who could later snatch more truffles from this patch when they've ripened.

All this stealth is due to the fact that truffles mostly grow wild (they're starting to be cultivated in a few places by treating tree roots with spores, but it's a long, iffy process). An official truffle hunter -- trifolau, as the Italians call them -- must take a test and obtain a permit to roam around in search of the fabulous fungi.

We tromp across a field to a cluster of oak trees, another of Roberto's favorite hunting grounds. "I am relieved," he says. "I was worried maybe we wouldn't find any truffles. Gaia is a little nervous with strangers around." As Gianni translates this, he comments that, in the famous truffle territory around Alba, truffle hunts are often staged for tourists with "planted" truffles. "It is like, like . . . like Pasqua," he huffs, his indignation overcoming his command of English.

"Easter," I guess. "It's like an Easter egg hunt!"

"Si, si," he replies, as Gaia scampers off and starts digging.

This time Roberto, who's been trying to follow our conversation, is late on the grab, and Gaia gobbles what must have been a chick pea-size truffle, despite his efforts to pry it from her jaws. Episodes such as this explain why Italians use dogs to search for truffles, rather than pigs, Roberto says. It's not uncommon for French truffle hunters to be missing a finger or two from tussles with their truffle-crazed porkers.

As we stride across the hillside toward a lone oak tree, we ask what type of dog Gaia is. "He says he only uses bastardi." Gianni translates. "They make the best truffle dogs. Bastardi -- you know?"

"Mutts," I tell him. What else could it mean?

"Only females," Roberto adds. "The males are too distracted by other smells." I nod and smile a knowing female smile.

The dogs are trained from an early age with tiny pieces of truffle, and by the time they're full-fledged truffle hunters, Roberto claims, they're worth about 3000 euros, or more than $3,500. So Gaia, who by now is wet, matted and muddy, is more valuable than many a pampered purebred. She proves her worth by bagging a white truffle, the most valuable of them all. Roberto gingerly digs it out, wraps it and places it in a pocket on the inside of his jacket. "I keep the white ones close to me," he says, smiling.

Rain earlier in the day rinsed competing smells out of the air, so the truffles are easier to find, Roberto tells us. Hunting is good at night, too, when there are fewer odors, "but there are wild boars and they can kill the dogs," he adds. Dusk is closing in, and Gaia disappears with Roberto into a clutch of dense brush. Like a gullible camper who's just been told a ghost story, I listen for the grunts of a cinghiale that could materialize from the underbrush at any moment and impale me on its vicious tusks.

Roberto and Gaia emerge, trailed by neither a boar nor a man with a bloody hook. The light is so dim that we decide to call it a day, and trudge through the mud to a modest home nearby, where Gianni wants to say hello to some friends. A woman comes to the door holding a partly assembled jacket lapel. "She does hand-finish work for some of the top Italian couture," Gianni says as he introduces us. Within just three hours, I've hunted legendary little lumps of astronomical value, escaped wild boars and come upon a magical cottage where Armani suits appear.

We bid goodbye to Roberto and tell him if he visits the United States, we will take him on a hunt for parking spaces, which are nearly as rare as truffles. He refuses a gratuity, which we'd conspired with Gianni to present, just as he'd refused an offer of payment when the expedition was organized. "It is my pleasure," he maintains.

At this point, I could use a spot more grappa, but we are late for dinner, where Silvana is going to show us what she can do with the precious fungus. Silvana had her own restaurant for 25 years, we'd learned, and her meals so far have been feasts, even sans truffles. She brings out two white ones for us to choose from, telling us they are sold by the gram. They sit royally on a small wooden tray beneath a glass dome. Paul dubs it a "truffle trap." Appropriate, because when Silvana lifts the lid, a cloud of captured truffle musk escapes and wafts out to seduce us. We choose our truffle and she carefully brushes it off, telling us in a combination of English, French and Italian that truffles should never be cleaned until just before they're eaten.

Silvana overwhelms us with a seven-course extravaganza, including three dishes topped with truffles, which she shaves at the table, letting the steam transport the potent truffle aroma up to our noses. The food is simple, so the truffles can star: small crepes, oozing with rich local cheese; homemade, hand-cut tagliatelli in a light sauce of butter and milk; and an egg, sunny-side up. This is the perfect finish to a successful treasure hunt. Except Paul isn't finished.

"Santa Silvana," he asks (having granted her sainthood by this point), "could I have scrambled eggs con tartufi for breakfast?"

Silvana looks puzzled. "For breakfast?"

"Yes," Paul replies, giving her the same deprived, heart-melting look Gaia flashed when she was pulled away from a truffle.

"Why not?" Silvana says, laughing.

Gayle Keck last wrote for Travel about Egypt.

At right, Gaia the Truffle Dog sniffs out the delicacy. Above, white truffles and eggs at Italy's Cascina Cichetti B&B.In the Piemonte region of Italy, truffle hunter Roberto Bovetti digs up a truffle as Gaia, his assistant sniffer, watches.