SAN MIGUEL DE ALLENDE, Mexico -- ''What happens in Mexico, stays in Mexico," David would tell me in a bar named Berlin three days before I was to leave thiscity.
But this is a week earlier. I haven't met David yet. Nothing's happening. I'm lounging in the back garden of the 18th-century house my parents have rented, drinking Negro Modelos and making Play-Doh highways with my 3-year-old nephew Jack (known here as ''Hack"). The idea is to distract Hack from stomping the leafcutter ants that march in formation across the patio that Maria and Isabella wash clean every other day.
Hack is content building bridges, and the housekeepers, if not content, are busy mopping floors. The ants are tireless in their devotion to whatever subterranean life force lives beneath the flagstones.
I should be working. Instead, I'm lazy as a queen ant. This is not difficult in San Miguel de Allende, which encourages idleness. In February, the skies are immaculate and blue and the air hovers at an ideal 75 to 80 degrees. Even in the dry season, the garden is a verdant Noah's Ark of specimens: a lime tree shading the courtyard, banana and palm fronds high above, aloe underfoot, ivy and bougainvillea cascading down the walls.
To stay busy, I read my book. Like all the tourists, I buy a straw cowboy hat. I suck down lethal, two-for-one, served-two-at-a-time margaritas at Harry's. But my gringo guilt gets the better of me. I'm embarrassed that after a couple of days here, I still haven't learned to say ''How much?" or recognize numbers higher than 10. I'm ignorant, and restless. Church bells mark the passing hours.
Of course, family time is good. All of us together, meals together, wandering together. Sitting on a park bench in the Jardín Principal, reading a Miami Herald with my dad. Meeting my stepmom after her painting class at El Nigromante. Dining on sopes and sangria with my brother and sister-in-law. But I have little purpose, myself, other than to be with them, here.
''Here" is this 80,000-strong city that sits on the semiarid plateau called the Bajío, 170 miles northwest of Mexico City. Its Spanish Colonial architecture of brick, tile, iron, and wood pumps new life into the tired words ''quaint" and ''charming." San Miguel is as history-laden as Siena, Italy, or Granada, Spain.
Everywhere is evidence of human habitation: church spires, wooden doors, stone lintels. The pigments washed across the stucco are the color of mangoes, tomatoes, cilantro, and lemons. Visually, the city pulses. Culturally, too. A vacation can be filled with endless folk-art shopping, gourmet dining, and English-language art classes, lectures, and concerts.
But among the gringos, retirees outnumber the under-40 set 10 to 1. Why have so many elderly snowbirds chosen San Miguel's winter nest? Matzo-flat Miami Beach this is not. The steep limestone sidewalks are treacherous. It's a wonder the cobblestone lanes of Centro (the 68-block historic district) don't twist more ankles and break more hips.
Once my brother and his family leave, time trickles to a drip. My parents are settled into their routines. I'm left to find my own peer group. Wherever that might be.
My solution is to get out. One afternoon, I set up my paints on the street outside our rental, trying to capture the yellow dome of La Parroquia in acrylics. ''A lot of people come here to paint," a stranger, Sebastian Lopez, says to me on his way home, carrying a bouquet of roses. ''I used to paint. But now I'm a lawyer."
Another day, I go shopping. I will transform the bags of produce I buy at the covered market into salsa, guacamole, cactus salad, and fajitas. Hunched women selling blue corn tortillas smile at my point-and-grunt method of communication; a teenage pastry shop worker is more annoyed. A farmer sells milk from the back of a pickup truck. Another man sells me churros from a cart. A woman hands me a steaming tamale from a plastic bucket. Other women, older, more beaten down, beg endlessly on the sidewalks.
I hike east from Centro, up Correo to a citywide lookout over the crooked streets and neighborhood shrines. There's the Plaza de Toros (bullfighting ring), the Parque Juárez (park), and the reservoir at Presa Allende shimmering in the distance.
The neighborhood on the way down is far from gringos. Children return to school from lunch. Workmen chisel stone. A cowboy hauls firewood with a donkey. I duck into a Day-Glo pink restaurant, El Burrito Bistro, run by Noren Cáceres, a Mexican-American with a degree in creative writing from Emerson College. ''A lot of younger people in their 30s and 40s are here," Cáceres, who moved here a dozen years ago, assures me. ''But they're not hanging out in the Jardín."
One evening my parents drag me to an art opening. In a renovated Colonial residence, five galleries are set around a stunning open-air courtyard. As the square of sky overhead turns indigo, the place fills with retirees. I approach the only man who looks younger than a baby boomer: David Maxwell, 34, an instantly likable American from Texas. His photo gallery, Galeria Filón, sells dreamy, sepia-toned images of peasants and cowboys.
David explains that he found his social circle through his girlfriend, Flor Mariana Alvarez Tejeda, 24, a bartender.
''So, where do people, you know, our age, go?" I ask.
''Meet me at Berlin," David says. Berlin is where Flor works. San Miguel has its two Irish bars, its Dunkin' Donuts, its Blockbuster. Why not a German restaurant?
The next night, I check it out. The joint is laid-back, with enticing shadows cast by candles, the kind of expat hideout Bogart might have haunted, had he spoken Spanish. David introduces me to his friend Ove Pedersen, a Norwegian surf instructor/photojournalist/flamenco guitarist whose girlfriend, also named Flor, waitresses here. I meet other expats: the director of a house-building charity, an artist from Toronto and her Australian ex-husband, a woman who supposedly inherited $50 million from her dead husband.
Conversation topics range from bribing the police to friends with private planes who smuggle in iBooks. My people, at last. Flor puts an ABBA, Blondie, and Parliament mix on the CD player. The wine -- or the town's 6,435-foot elevation -- casts its dizzy spell. By the end of the night, I know everyone in the bar. Did I dance with any of them? And then?
What happens in Mexico, stays in Mexico.