In Ecuador, or maybe it was Guatemala, beggars grabbed him by the ankle when he stepped off the train. "No sea malito," they said with their bellies and palms out. "Don't be naughty." Give me money.

In Bocas, Mexico, at the town dump, which is part of the railway station, he watched two dogs yank at one heap of garbage, two pigs root at another. Both of the dogs were lame; one pig was missing an ear. The mutilated animals were appropriate to the mutilated town, he thought.

Paul Theroux, 38, restless prolific novelist and best-selling travel writer who doesn't like traveling very much, sits in a window of the Hay-Adams. The sun is cracking in. He has on English clothes and an English accent. Never mind that he is from Medford, Mass. Before him is a gay tin of pipe tobacco. Outside the window, a man in khaki work clothes hoses down a bush; the water splats at the glass.

"I know exactly what I'm going to have," says the author of "The Great Railway Bazaar" and currently, "The Old Patagonian Express." "Grapefruit juice, scrambled eggs -- just the eggs -- and toast."

"You don't want the hash browns? The hash browns come with it," says the waitress.

"Okay, give me the hash browns."

Funny, the man who has been to Burma and Singapore and La Paz, who has ridden the Trans-Siberian Express and the Aztec Eagle and the Balboa Bullet, doesn't particularly think of himself as a good traveler -- even if he can change his mind fast.

"I think of a good traveler as one who can get to a place and get a good night's sleep, no matter what happens," he says. "I'm always planning my next move, my next escape."

Like the time he got to Mexico City at dark, after a day and a night overland from Nuevo Laredo, decided the whole place was huge and cold and foul, and went straightaway to the ticket counter and bought a sleeper to Veracruz. The hell with Mexico City. "It was cheaper than a hotel room and, anyway, people said that Veracruz, on the Gulf Coast, was much warmer," he writes in his book.

The going, not the landing, is what matters.

The waitress brings the food. "Do you have any Tabasco sauce?" He applies it with a surgeon's skill. "A good traveler would have a greater suspension of disbelief than I have. He could eat anything, sleep anywhere. There is a sort of selfishness about him that I don't have. I'm always feeling guilty about leaving behind my wife and children."

In Guatemala City two winters ago, taking the two-and-a-half-month rail trip through the Americas that is now a book, he decided to ring London and see how his family was. His wife Anne, who is English and a radio producer for the BBC, said she loved him. Marcel and Louis had made a snowman. The call cost him $114. That night he made a dreary round of bars.

None of it sounds very romantic, let alone exotic. Paul Theroux's travel accounts are cranky accounts of trains that barely run, much less on time, of hotel rooms with rats, of swarming prostitutes. " . . . the piles of orange peels and blown-open coconut husks with fibrous hair . . . that gray trickle of waste water gathering in a green yellow pool . . . the four huts, the limping dog, the whining pig . . ."

Why push on so? He's not exactly sure. It's just something writers do, he imagines. "Not for any profound reason certainly, do I do it. I think from an early age, I wanted to see what was going on out there. I had grown up in a large family, seven children. We were always doing things together. That's wonderful, but you can never quite feel alone. Travel affords a great privacy. And anonymity."

The first place Paul Theroux ever went, he says, is Puerto Rico. "I could get there from Boston for $49. I went and stayed the whole summer. Later, I was there for Peace Corps training."

That was a decade and half ago, before he began the stream of novels -- eight since 1967 -- and the collection of short fiction and the two travel books that have made him a rich man, with a house on Cape Cod and another in London, before he has even hit 40.

Theroux came to Washington from New York on the shuttle the other evening. He was exhausted. He had a beer and a sandwich and didn't feel like turning in. The traveler's dilemma: What to do? He went strolling. He stopped outside the Sheraton-Carlton and watched the anointed and would-be anointed trying to get into the Polo Club. He thought it was wonderful and comic, this new priestly class with its flowing robes and money. He'll probably write it into a book.

Theroux has a brother in Washington, Gene Theroux, who is a lawyer, and an ex-sister-in-law, Phyllis, who is a writer also. Another brother, Alec, is a novelist and teaches at Phillips Academy in Massachusetts. He doesn't believe in literary genes, though. His father is a retired shoe repairman.

And his son talks like a barrister, tucking "rathers" and "awfullys" all over the place. ("Some days I feel awfully not like Richard Halliburton, But Willy Loman.") How does Medford, Mass., come by such impeccable talk?

"Oh, your original accent gets abraded, I think, when you move about. At home, in London, when I'm on the phone, I've been told, 'Why don't you go back to Jamaica?'"

Gentle self-deprecation: He may have learned this from the English, too.

In a way, his books are like that. Theroux's literary affinities are very English. It is like Graham Greene without the sin, as one critic has said. There is the acerbic wit of Evelyn Waugh, the exile's mannered eye he probably got from Henry James.He doesn't go for the boomer book either. That's not English at all. He just nibbles away, publishing year after year.

Theroux's novel of some years ago, "Saint Jack," has just been released as a film directed by Peter Bogdanovich. The movie won an award at the Venice film festival -- and suffers bad reviews over here.

He hoped to see his brother Gene the other day, but at the last minute Gene had to tear off to Tokyo. Something to do with Ringling Brothers, a client, Theroux says. Maybe the whole family is nomadic.

He got the idea for "The Old Patagonian Express" when he discovered it was theoretically possible to travel by rail almost uninterruptedly from the subway station near his childhood home to the pampas of southern Argentina. That was a tempting thought, "merely skimming south, a bird of passage generalizing on the immediate," while the rest of us slogged through winter. What Theroux likes most about trains, he thinks, is the continuous vision they provide -- images across a curved surface of earth. There's also the poetry of departures. No mechanized, climate-controlled, time-zone-wrenching air travel for him.

He's no E. M. Frimbo, though, that hopeless, hapless, fictional, incessant rail rider for The New Yorker magazine, who loves them all. Listen to Theroux's description of the 7 a.m. to Zacapa: "The padded seats were torn -- springs and stuffing protruded; the wooden seats were shaky; all the seats were wet. The car itself, a relic from the 1920s, was neither quaint nor comfortable but merely a small uncared-for box, stinking of dirt . . ." To a rail buff, that is sacrilege.

He had a scruff of mustache and a pair of English leakproof shoes then (they sprung a leak), a battered suitcase and his copy of Boswell's "Life of Johnson," a leather jacket and his tube of morphine-spiked English "cement" to past his stomach back together after tourista . And he still wasn't happy.

Now that he thinks about it -- he has finished breakfast and is sitting erect; his tinted glasses bounce yellow light -- what does travel have to do with fun anyway? Fun isn't the point. The point is discovery. Discovery has its own rewards. "Travel is glamorous only in retrospect," he says, a little resignedly.

"I spent the whole summer on the Cape sailing my Sunfish. Time passed very quickly. But it's only memorable as a vague pleasure, not something detailed and fleshy."

If it weren't for travel writers like Antonio Pigafetta, then how would we know what Magellan's voyages were like? If Trollope hadn't gone to the West Indies, or Dickens to America, and then written beautifully about it, the world would be a poorer place. Robert Louis Stevenson and Mark Twain are excellent travel writers, he thinks. D. H. Lawrence? "I find him too biased and mystical. He doesn't give the place a chance."

At the moment, Theroux has no burning desire to go off. He's going back to London to watch the kids go off to school and his wife off to work. (She takes the 9 o'clock train.) He's got a new fiction idea. Eventually, the wander itch will come again; he'll scratch.

"You go off. Like Ishmael. You take to the sea when you think you're going to hit somebody on the head."

Paul Theroux's grin is wide as a river, uncharacteristically British. "You can't call me Ishmael, but . . . "