He stands alone on the platform waiting for the 5:58 train.
As it chugs to a stop, Chris Guenzler waves, as a child might, to the engineer, who rings the bell in response.
Guenzler climbs aboard, on his way to nowhere, really.
Every weeknight, he rides 184.6 miles like clockwork -- first from Santa Ana to San Diego, and then immediately back home. It's a 3-hour, 50-minute trip that he has repeated for six years now. Each night it ends the way it began: with a wave to the engineer, who rings a bell in response.
Another night, another ride, another day sober.
By any standard, Guenzler, 43, of Santa Ana, is a train fanatic. The affectionate term is "buff." The less affectionate term is "foamer," for one who foams at the mouth over trains.
He has logged more than 592,000 miles by train. He's rolled along every mile of the Amtrak system - all 22,000 miles - not once, but twice. And he's ridden trains in all 50 states.
"I can't name anyone else who's done that," says Rich ard Borstadt, director of the San Diego Railroad Museum. "It's a pretty rare thing."
Yet it is Guenzler's nightly excursions that set him apart.
Everywhere around him, passengers tap on laptop computers, talk on cell phones, read or sleep, all with destinations - home, work or a night on the town. But not Guenzler, a teacher's assistant at McFadden Intermediate School. He is simply staying out trouble.
He once drank two bottles of whiskey a night. When he sobered up in 1995, he began riding the train to San Diego to get out of the house on Friday nights, where he used to drink. It became a nightly ritual. Now it's a way of life.
"Everyone on the train knows I'm sober," he says, sitting in the upper deck of a Pacific Surfliner, one of a brand new fleet of Amtrak trains. "I'm open about that. I wanted everyone watching me."
When conductor Woody Lambert comes by to collect tickets, Guenzler smiles and calls out, "Hi, Woody."
"It's been six years tomorrow," he says of his sobriety.
In those six years, he's met and made many friends on this route. They see him roaming the cars in sweatpants, sneakers, a backpack and often a Jethro Tull concert T-shirt. (He has only missed one Jethro Tull tour in his life, when he was - naturally - on a train trip.)
Many regulars know him -- and those who don't, recognize him.
"I've been riding this train for eight years and I still don't know why he rides," says a laughing Turguy Goker, 48, of Solana Beach, after the pair chat in the cafe car. "I never wanted to ask him why. I like it to be a secret."
Others, such as commuter Erv Poka, invite Guenzler to help with crossword puzzles, and watch Guenzler's slide shows, which he brings right on board and beams on the car door."There are all kinds of personalities here," Poka says. "Some have their favorite seats, some sleep, and the annoying ones get on their cell phones. Chris does other things. He'll pitch in and help with passenger problems, people who are lost or have misplaced their baggage. He'll help when the doors get stuck."
Guenzler is at times friend, raconteur, tour guide, goodwill ambassador, historian - even waiter of sorts, as he walks into the business-class car and pours a cup of scalding black coffee.
"I gotta get the engineer a cup of coffee," he says over his shoulder, pushing through doors between cars to the front of the train.
From this vantage point, he has watched waves in San Clemente crash against the side of the train during El Nino storms. He also watched a landslide that stopped the train in its tracks.
"The engineer and I watched a patio come off a house," he said.
He and engineer Doug Busler briefly discuss names for a caboose: crummy, hack and waycar.
"I don't think there is anybody as thorough as Chris is," says ! Busler, one of many on board who test Guenzler's railroad knowledge.
Guenzler's memory appears to be photographic, at one point recalling the stations and even the stop times of a route from Chicago to Oakland.
He has seen great beauty and tragedy along the way. He recalls the 876-foot New River Gorge suspension bridge - second highest in the country - in West Virginia, and the 232 miles of canyons along the Colorado River - the most beautiful stretch in the country, he says.
Guenzler has also seen a man throw himself in front of a train in Oakland.
He was on board a train that hit a surfer in San Clemente last June. The train struck the young man's surfboard, which spun him into the train as well, but officials couldn't find him at first.
"The conductor asked me to help look for him," Guenzler said. "He was behind the train. He survived. He broke his collarbone."
As Guenzler returns to his seat, he stops to chat with crew members. He tells them if there are any delays, they may see him ride into his sixth anniversary of sobriety at the stroke of midnight.
"My mom usually bakes a chocolate cake for me," he says.
Guenzler lives at home with his mother, Nancy Guenzler. She introduced her son to trains when he was 3.
"He had a bad hearing loss and speech problems," she says. "To get him to talk, I'd walk him down the street every day to the train tracks to see the trains go by. Sometimes we'd go twice a day.
" From then on, he was hooked.
His bedroom still is filled with train photographs, train videos, old tickets, trip logs and maps.
He can tell you where he was when he hit 100,000 miles (Lujan, Mexico), or 250,000 miles (just out of Irvine, bound for San Diego), or any other plateau. It's all documented in miniscule print in spiral-bound notebooks in his closet.
He began tallying his miles in 1980 after a trip to Pocotello, Idaho, to visit his brother. En route home, the train lost its air conditioning in the desert. A man tore off his shirt, leading a woman on board to do the same.
"You tell me," Guenzler deadpans, "if you had a first trip like that, wouldn't you want to come back for more?"
In those days, he was drinking. He rolled through 42 states, but each time he was intoxicated. He was even tossed out for drunkenness one night in New Orleans.
As much as he rode then, it was sobriety that pushed him to the stratosphere of rail riding. During treatment for alcohol in 1995, he was asked to set a goal. Guenzler blurted out, "How about if I go back to every state that I drank in and go sober?"
"I never heard of anybody doing that," his counselor answered. "Sounds good to me."
He was off to the races. He returned to the 42 states he'd visited, and kept going until he hit all 50.
He also started his nightly jaunts to San Diego. A round-trip ticket from Santa Ana to San Diego costs $32, but Guenzler's weekly rail bill only runs about $80 - less than he used to spend on alcohol, he notes. Four friends buy him tickets for staying sober. One is a woman he met on board six years ago.
"She's very wealthy," he says of his benefactor, who prefers to remain anonymous. "I see her about once a month. She just passes me an envelope and says, "Here you go. Keep staying sober!"
Guenzler's hero is former New Yorker magazine writer Rogers E. M. Whitaker, who logged 2.7 million miles on trains, and wrote the Bible of train-riding books, "All Aboard with E.M. Frimbo: World's Greatest Railroad Buff." "He's the granddaddy of train riding," says Guenzler.
"Right now, my next goal is one million miles. Then maybe riding in all seven continents." Right now, there are no trains on Antarctica, but Guenzler says if he could find a sponsor, he would bring a miniature live steamtrain and a few hundred feet of track to Antarctica.
"I'd call it the South Pole and Northern," he says. "I could call it anything I wanted."
He hopes one day to write a book titled "Why a Train?" from the 700 handwritten pages of notes he has accumulated over 20 years.
"It's about my experience on trains and the story of my sobriety," he says.
If his years of riding have taught him anything, it's patience, he says, because there are often delays. But not tonight. The No. 452 pulls into the Santa Ana train station precisely at 9:48, right on time.
Guenzler is off his seat before the train stops moving, and out the door. He waves to the engineer, who rings the bell back.
Riding home to Santiago Avenue in his Geo Metro, it is as if Guenzler is the engineer when he beeps his horn on 20th Street to let friends know he has returned safe and sound.
It is drawing near midnight, the hour of his sixth anniversary of sobriety. The house is warm and it smells sweet as Guenzler pushes open the front door, calling out a hello to his mother.
He walks into his bedroom, pulls out his travel log and calculator, and immediately enters his new total mileage: 592,427.8.
Wafting through the hall comes the smell of chocolate - the smell of a chocolate cake. The smell of six years of sobriety.
It's 11 p.m., time for bed after another long night of going nowhere - nowhere, but in the right direction.