Why do some restaurants have you at hello and others never get to first base? The campaign starts with good PR and a monster e-mail blast. It ramps up with text messaging, Tweeting, blogging, and Yelping once the place opens. (Do you remember when people used to phone each other and talk about restaurants? How quaint.) Finally there’s the mysterious mojo that results when the crowd, the mood, and the food—let’s not forget the food—all mesh. Whatever the combo, three-month-old Perla’s Seafood and Oyster Bar has it: At seven o’clock on a Friday night, every table was reserved and there was more than an hour’s wait.

One of my favorite perches is the cold bar, where you can watch the hardworking oyster shuckers popping open a changing array that might include briny Lady Chatterleys, diminutive Kumamotos, and buttery-textured Malpeques, plus a clam or two, like Old Salts. In fact, if I were having lunch here in July, I’d go for something easy and icy, say, an order of oysters and then the crab Louis, which consists of gorgeous lump crabmeat gilded with a lemony homemade mayo on a base of fried green tomatoes—a fun Southern send-up of the ingredients. (I’d almost suggest the sweet, fresh gazpacho too, but that recipe is in need of some zing.)

If I were doing dinner, I would get serious with the entrées of pristine seafood being turned out by executive chef and co-owner Larry McGuire. The Market section of the menu keeps it simple: You choose a fish and a sauce (or several). That worked out wonderfully the night I had the roasted wreckfish, a white-fleshed, halibut-like critter. All four sauces were good, but the “salsa verde” (actually a garlic, herb, jalapeño, and olive oil chimichurri) blew me away. Not far behind was the dusky-spicy “red chimichurri,” which is not strictly a chimichurri but rather a guajillo chile sauce. (And may I interject a crabby question at this point: Why are chefs and restaurateurs compelled to monkey with names? I’d really like to know.) Finally, the Plates section of the menu is where I would head if I were in the mood for something creative, like a griddle-cooked striped bass with an unexpected sweet fig glaze and a side of lightly sugared bruléed endive (the fish was excellent, but the lettuce proved more an interesting experiment than the next likely food rage).

Whatever aspect of the menu I explored, I would hope that by the time I finished I could move outside to the broad front deck for a cappuccino or a postprandial cocktail. The airy dining room has a great yachty-funky Texas coastal feel, but I can never resist a deck on a summer night, when the heat is fading and the crickets and tree frogs are hitting their stride. It’s part of the mysterious mojo that you just can’t buy. Bar. 1400 S. Congress Ave (512-291-7300). Lunch Mon—Fri 11:30—3. Dinner 7 days 5:30—close. Brunch Sat & Sun 11—3. $$—$$$ W+