When night descends, I'm thinking about L.A. Story, the 1991 movie that Martin wrote and starred in as Harris K. Telemacher. He attempts to land a reservation at an upscale L.A. French restaurant called L' Idiot (pronounced Leedy-O), only to be interrogated about his finances by the Fourth Reich Bank of Hamburg. "He can't have the duck!..." the chef snorts. "He can have the chicken."

I'm sitting in Spago Beverly Hills, which, while pricey, is a great, easygoing place (no financial statements required), perfect to watch the crowd that passes by the bar. A suited local storms in like he's in a parade, greeting three middle-aged, easy-to-spot out-of-towners with the line, "Welcome to Beverly Hills!" But Martin says the movie restaurant L' Idiot is merely "exaggeration," another case of fiction being more important than fact.

"The Grill is a very important restaurant for showbiz. It's just that they have great, great food, and it caters more toward the business end of show business than the celebrity end, but it's really a nice, nice restaurant and they keep the quality of the food really high. It's kind of on the alley. You don't really go into the alley, though."

I pull up to the Grill's valet parking stand on the alleyway behind Wilshire Boulevard and step into another stage set: a New York steak house, transplanted. It's packed and noisy, with precisely one empty stool at the bar, which holds a woman's purse. She removes it with a flourish and says, "Sit right down!" without taking her eyes off the basketball game on the television overhead. By 7:30, agents, studio heads, lawyers, and their clients are streaming through the door, taking every available table and leaving a long waiting list.

Back in the convertible, I toss a five to the valet guys (the fee is $4.50 everywhere) and pop in the cassette to see where Martin is sending me next, which I hope is to dinner. But he's still talking about shopping.

"It's a walking town, too," he says. "You can walk around Beverly Hills. It is very nice after dinner to just take a walk and window-shop. You can go down Rodeo, up Beverly, and just look in the windows. It's very quiet in the evenings."

Rodeo Drive is so quiet at 7:45 that almost every parking spot is empty, quite the opposite of only a few hours before. Back then, every spot was perpetually taken, and I was blasted with a dirge of honking if I dared to even pause a millisecond for a spot to clear. Strolling up Rodeo, I immediately realize Martin is right: It's better at night. The air has turned chilly, like a New En­gland summer, and I have the famous street all to myself. I walk beneath endless designer­ logos, window-shopping the bedecked windows. Then I climb the street called Via Rodeo, the hilly cobblestone shopping village of high-end boutiques, salons, and bistros, which, a tour guide proclaimed in Pretty Woman, "is the first new street built in Beverly Hills in 75 years!" There's a re-creation­ of the Spanish Steps, a fountain perfect for tossing coins into, two hours of free valet parking, and tables full of outdoor diners, which, on the evening of my visit, included one Via Rodeo tenant, Elizabeth Taylor's longtime hairdresser, José Eber.

It's nine by the time I get back to the car, and Martin's dispatching me away from Beverly Hills Proper and into Beverly Hills Adjacent.

"There are Beverly Hills-type restaurants like the Ivy. It's really nice, but that's what they call Beverly Hills adjacent to West Hollywood. There's Chaya, which is a really nice restaurant adjacent to Beverly Hills."

The Ivy is straight out of the movies. The see-and-be-seen are sitting at flowered tablecloths on a patio beyond a white picket fence. Yes, it's Beverly Hills Adjacent, but in a town where fiction always triumphs over facts, the Ivy is, as Martin promised, 100 percent Beverly Hills. I'm shoehorned into a tiny, pillow-festooned table that adjoins a table of six wildcat Beverly Hills women, their voices as loud and emphatic as machine guns. They are women straight out of a Steve Martin novel, where people have names like Loki and Del Rey. They riddle the topics of the day: men, music, sex, ­Botox, pilates, and how their feng shui guy just can't seem to get things right. I hang on to their every syllable, as if I'm part of their convivial group, even offering to pony up a five-spot when, divvying up their bill six ways, one of them falls $5 short. They stare at me like I'm an alien, an adjacent instead of Beverly Hills proper, and I want to proclaim, "Steve Martin sent me!" But they're gone in a percussion of high heels on concrete, one accidentally slapping me in the face with her scarlet snakeskin purse as she rushes off.

Since Martin isn't around to pick up the tab, I pay my bill and bid good night to the valet parkers.

Back in the car, Steve provides a perfect coda to the night.

"That's another thing about Beverly Hills. People are really, really nice. At least to me."