The Lobster Barn. El's Fried Clams. Finestkind Fish Market. As you drive along Route 1, the narrow road that connects the coastal villages of southern Maine, the seafood joints and bait shops breeze by like gulls over the Atlantic. Many are quiet, their parking lots sprinkled with a few afternoon motorists.

But in the tiny town of Cape Neddick, about 50 miles south of Portland, a gaggle of cars and eager-looking lunchers crowd the roadside next to a ramshackle red shack. To the untrained eye, the place has all the allure and sophistication of a woodshed. Yet the line out the door intimates that something special must occur inside.

And so it does. For the loyal legions who daily brave the 30-minute waits and the cramped confines, Flo's Steamed Hot Dogs proves that a cylinder of undistinguished meat prepared with a little flair can achieve culinary heights that would turn lobsters green. In the land where cod and clams are king, Flo's is the defiant misfit, built on attitude and a near-magic recipe that turns even the most refined palates into slobbering, drooling dog addicts.

Don't be misled. The hot dogs ($1.75) at Flo's are ordinary hot dogs. And the steamed buns, though cotton-candy soft, are hardly worth lining up for. The marquee attraction is the special -- and highly secret -- sauce. Dark and a bit chunky, it gently teases between sweet and sour. Paired with mustard, it becomes hotter. Matched with mayo (known as the "special"), it turns tangy-sweet. It's a bit relish-y, vaguely chutneylike and altogether mysterious.

Only two people know the ingredients, said co-owner Gail Stacy: herself and a company employee she has hired to produce a bottled version (on sale at Flo's for $7.95). When pressed, Gail will say only that it contains onions, molasses and "spices."

This much is known. The red shack began its commercial life in 1947 as a hot dog stand called Bob and Ann's. The original owners concocted the first version of the celebrated sauce.

But it was the late Flo Stacy, Gail's mother-in-law, who elevated the joint into the temple of the tube steak. Flo bought the restaurant in 1959, gave the place its current moniker, tweaked the sauce's ingredients and presided over the quiet ascension of one of New England's most rewarding (and refreshingly cheap) culinary experiences.

Flo was a legendary curmudgeon. With a quick temper and a vocabulary saltier than an ocean breeze, she could tell off hardened fishermen and sailors with a feistiness that has become the stuff of lore. Gail, who slung dogs at her mother-in-law's side for decades, was often in the line of fire.

"I used to go home crying a good many days," Gail says. "I wasn't used to such outspokenness."

Gail and her husband, John, took over the eatery in 1973. Flo continued to add her considerable energy -- and vitriol -- to preparing her signature condiment. As Flo would playfully tell her family, "a lot of hate" went into each batch.

Flo passed away in 2000 at 92. She worked the day she died, Gail said, cutting the dogs and chopping the onions, as always.

If hate has been one of the secret ingredients, the sauce's devoted followers are clearly gluttons for punishment. There are regulars who show up nearly every day, and many patrons have been coming religiously for decades, sometimes traveling ridiculous distances to do so. Once, two former locals who'd moved to California showed up for the lunchtime rush.

"They flew to New York and rented a car to come up," Gail said. "Then they went right back to New York City. They were there on business and they figured that they were pretty close [to Maine]."

The line often starts forming well before the screen door opens for business at 11 a.m. "If I'm within 15 miles of this place, I'm here," said John Kyle, who was eagerly queuing up at 10:50 on a recent morning.

Don't show up at Flo's with hopes for a varied and balanced meal. Other than dogs, the menu offers only potato chips, and drinks are limited to soda, milk, coffee and iced coffee. A seating area is composed of a few dilapidated picnic tables next to the shack. Most folks eat in their cars right there on the roadside.

Gail said she doesn't count the number of dogs she sells on a given day, but it's not uncommon for a patron to order three or four at a time. The most hot dogs she has ever served one customer is 230, though the batch was shared with a larger group of fans.

This summer, a guy set a Flo's record by devouring 20 dogs in 38 minutes. Before that, the longstanding record had stood at 18 in 45 minutes.

"We don't promote that, though," Gail said. "If someone dies, I have to live with it."

-- Seth Sherwood

Flo's (1359 Route 1, Cape Neddick, Maine) is open daily except Wednesdays, year-round, from 11 a.m. to 3 p.m. No phone.

Maine might be known for its lobster, but in Cape Neddick, it's all about the dogs at Flo's Steamed Hot Dogs. Folks travel great distances to line up for an order -- or two. Co-owner Gail Stacy, bottom right, keeps her mother- in-law's special sauce a secret.