It would be easy to conclude that everyone who pushes through the battered screen door into the Dixie Girl Cafe, the setting for the savory comedy titled "Last Days at the Dixie Girl Cafe," is either stark raving bonkers or well on the way.

Consider Jeri Lee, the proprietor, who first hands out daffodils to the audience of Horizons, that ever more confident theater group operating out of the Grace Episcopal Church, where "Dixie Girl" opened last night. A Georgia cracker with a mile-wide smile and a heart as warm as a fritter, she goes on to confide that the end is near and that she is carrying the Lord's child, as prophesied in the Book of Revelation. Since appearances demand a husband (the divinity has taken care of everything else), she is about to close down her beloved cafe and, on the shortest of acquaintances, marry one of her customers.

Wayne Blossom Senior, the lucky man, also anticipates the imminent destruction of the planet, but, as it happens, is handling matters differently: He sells fallout shelters. Although it is 1970, he continues to curse FDR for giving away the country's A-bomb secrets and allows smugly that he knows of documents proving "Eleanor Roosevelt was a man."

If this seems hardly a match made in heaven, Jeri Lee is quick to point out, "I'm not marryin' him forever. It's just until Judgment Day."

Wayne's two grown children are no less favored in the loose-screw department. The one they call (despite all physical evidence) Little Lanette hasn't lost her zest for baton twirling, but ROTC has definitely given her new purpose in life. As for her lunk of a brother, Wayne Junior, who runs the next-door gas station when he is not trying to cheat on his oil-spotted helpmate -- he claims the end of the world has already come and gone. He saw it from the deck of a Navy ship in the Pacific, when the government exploded eight H-bombs in a row. (Well, he didn't actually see it, crouched in a fetal position as he was. But he felt it on the back of his eyeballs.)

What you have every right to expect from this assortment of rubes and zealots -- a broad caricature of the Bible-thumping, narrow-minded South -- is precisely what you don't get from Horizons. As directed by the gifted Dorothy Neumann and acted by a humdinger of a cast, "Last Days at the Dixie Girl Cafe" keeps its feet firmly on the soil, even if the characters are entertaining some decidedly mad delusions. Instead of going overboard, which is the usual temptation with works of this sort, the Horizons production is constantly pulling back, reaffirming the connections these loons have with reality.

It's a neat trick, and it proves the salvation of playwright Robin Swicord's work, which is fairly ramshackle in its construction and skimpy, indeed, of story. The characters enter and exit sometimes on the baldest of pretexts, and the revelations they have to spring on an audience tend to come out of the baby blue. The play wants to hew to a naturalistic format that Swicord hasn't quite mastered.

She has, however, got a bead on her five original characters. Once they take their places in the fly-specked Dixie Girl Cafe and get beyond their immediate motivations for being there, you will find them a curiously authentic crew. They are all possessed, but in their misguided ways, they're doing their best to stay afloat, and Swicord feels affection for them all. She recognizes their shortcomings (and derives some rich comedy from them), but she also knows there's love rattling around in their souls. For that, she is willing to forgive a lot.

There isn't a whiff of patronization in the Horizons performances, even though this is one of those worlds where mothers drop their babies in the driveway and then inadvertently run over them with the car. Betsy Nuell, as Jeri Lee, floods the stage with generosity. Following the Lord's directives, fuzzy as they may be, is her main preoccupation, but that doesn't prevent her from lavishing her compassion (or her recipe for jello cubes) on others. Nuell gets the constant caring just right, although occasionally the fervor of her religious faith left me in doubt.

Likewise, Nick Olcott -- decked out in a rumpled cream suit and a tie that looks like colored lightning -- suggests that the demagoguery of Wayne Blossom Senior is actually an outgrowth of his concern. He does want to protect his children and save his fellow man. If he gave Little Lanette her coming-out party in a fallout shelter, it was, after all, his manner of assuring her future on two fronts at the same time.

Barbara Klein makes the graceless Lanette an appealing bubblehead. And Jane Beard, as the forsaken wife of Wayne Junior, is wonderfully sullen (she nibbles away at a stick of gum like a rat taking out its aggressions on a cheese stick), until she undergoes a religious conversion, and then she glows like an altar light.

But it is Brian Hemmingsen, as the boorish Wayne Junior, who forges the deepest and truest portrait. As he demonstrated several seasons ago in "Hello and Goodbye," Hemmingsen has a remarkable ability to portray lumpen oafs with extraordinary sensitivity. On the outside, he's every redneck gas station owner who found his life congealing in grease. But inside, he is raw with confusion and hurt. For his performance alone, you will want to drop in on the odd doings at the Dixie Girl Cafe.