Welcome to fantasy land.

Not that you'd suspect it here in the drear high-rise canyon of E. 43rd Street, with the litter scraps flapping like bat wings. But 40 feet above the scum-gray asphalt, behind a plain apartment door, is a private cosmos of baubles and whimsy where reality and fancy coalesce. A stuffed bunny perches on the arm of the sofa; a deep-shag Wookie lolls in the center. On the walls are paintings from the Tolkien calendars. And on every ledge and bookcase shelf are bulls, a score of them, ceramic and wooden, a silent stampede of figurines.

Presiding over this gimcrack menagerie like elfin monarchs are Judy-Lynn and Lester del Rey--the conjugal core of Del Rey Books, Ballantine's hard- and softcover s-f line whose phenomenal prosperity and seemingly incessant string of hits are the talk of the industry this summer. She, a diminuitive dynamo of cheer festooned in gold rings, chains and earrings, is the house's editor-in-chief, and one of the most universally envied of publishing executives. "Yeah," she says, bluff and chipper, "I used to be a Jewish princess--now I'm a Jewish empress." He--the rumpled and cantankerous veteran science-fiction writer with a ragged tuft of chin-whiskers and the eyes of a dyspeptic Rasputin--is the line's fantasy editor.

Judy is the hottest star in a genre gone nova: from 348 titles in 1972 to 1,047 in 1982--a year in which six of the 15 bestselling fiction hardcovers were s-f or fantasy, and two of them were hers. She's signed George Lucas' material from "Star Wars" to "Return of the Jedi," the recent number-one paperback best seller. She has a mortal lock on Arthur Clarke, Isaac Asimov, Robert Heinlein, Stephen ("White Gold Wielder") Donaldson and more. And after 10 years at Ballantine, her advice today to booksellers becomes tomorrow's stock on the shelves.

But that's mere reality. This is the del Reys' magical habitat, and the surprises are about to begin. Judy is serving lunch, bustling in with bowls ("When I get to heaven, if there's no pasta, I'm leaving!") which she lifts nearly shoulder-high to reach the table top. She is well under four feet tall--a fact one fast forgets in the auditory avalanche that follows. Both talk at once, trampling over each other's remarks like they were being paid by the word. Each seems to ignore the other; yet no comment passes without a superbly timed sarcastic contradiction. "We do agree," she says, "but not in front of people."

It is best to agree with Lester, a spry 68, fond of playing the Sanctimonious Old Coot with an opinion on everything (most of them ratified at the cash register). A native of rural Minnesota, he was writing for a decade before Judy, 40, was born. And "I don't need a word processor. I never rewrite! I've got 50 books over there, and I only rewrote one of them." . . . But then Judy is saying how "in the old days of science fiction, if they needed an editor, they'd go the mail room and find some kid who read the stuff." . . . But he's explaining the special keyboard he designed to "put the eight most commonly used letters right under your fingers," and how in the '50s his fantasy magazine beat its rack rivals, sneering that their covers "looked like Rorschach tests for dogs."

And then, suddenly, "Lester--did you feed the calves?"

Calves? Judy has disappeared into the kitchen, returning with a gleaming tray on which sit three tiny silver bowls. Quiet now, Lester carefully spoons a dollop of lunch in each bowl and takes them into the living room, where a sort of bovine shrine has been erected between the two easy chairs. On it are three identical figurines of bulls, about three inches high, each with a thatch of mink fur between the horns. The little dishes are set in front of them. "They're the papal bulls," says Judy. "That's Innocent, that's Boniface and this is Urban." They are garlanded in miniature kerchiefs and neck chains, and each has a teeny teddy bear half its height "to sleep with." Urban is the top toro--"he's the Alpha," she says. "He wears the horn rings." And has a business card: "Urban Del Rey, Ganze Macher. Represented by the Scott Meredith Literary Agency."

The del Reys step through this ritual as unselfconsciously as somebody else would put out the cat, then return to the table and the stereophonic nattering that, one begins to realize, is a habit of play and a dialect of love.

"Show him your card," she says. He fumbles for a copy: a simple white rectangle with his name and the single word "EXPERT." And her voice lights with pride in describing his 1951 novel about the first moon landing. He set it in 1964, but got the captain's name right: Armstrong. "So everybody says, 'Wasn't Lester prescient--isn't this a wonderful example of science fiction predicting the future?' But Lester contends that what it is, is that he and NASA thought the same way: They're gonna get a white Anglo-Saxon Protestant to be the first man on the moon!"

Both attribute Del Rey Books' success to a simple and dogmatic literary credo. "We publish the kind of books we like to read," says Judy. With Urban now at her elbow, she slides into a hard-boiled boardroom tone. "First, we are going to provide entertainment. We are not interested in meaningful, relevant, significant. If you want to send a message, use Western Union. Stories should have beginnings and middles and ends and the packaging should attract readers."

Packaging! Lester is up now, away from the table, pulling other houses' books off the shelves and gleefully insulting their covers. Judy, ignoring him, picks up Urban, turns him toward a paperback cover, and emits a Bronx cheer.

"She is very blunt," says a New York agent. "She once sent me back a rejection letter that made me turn colors." "Brutally honest," says another agent, Richard Curtis. "You seldom get a gracious rejection from Judy. What she says, in effect, is 'Don't bother me with stuff like this.' " Judy, smiling with transparently bogus sweetness, says, "Do I look like a barracuda?"

Not surprisingly, she has enemies. Her hegemony, they say, has cheapened the genre. Author Robert Silverberg changed houses because of her taste: "Judy and I are old friends, but we parted company over that. Despite her private predilections for 'Ulysses' and 'Finnegans Wake,' her books are not really known for their literary merit." David Hartwell, outgoing editor of Pocket Books' highly esteemed Timescape s-f line, finds her emphasis "too narrow. The basis of her success is the repeatable product. That response to the marketplace is no different in kind, in many respects, from Silhouette Romances." And many s-f writers of the more literary persuasion feel threatened by her clout with booksellers.

Lester, smouldering during this recitation, finally explodes: "Most of them, in this little clique of clannish people, would like to see us fail. It would justify everything that they say. They don't read what the average reader reads. They're much too sophisticated"--this last uttered with grinding sarcasm.

Your average s-f fan gets the habit in his teens. But until Judy was in her 20s, "the only science-fiction awareness I had was that I used to watch 'Captain Video and the Video Rangers' "--for whom, it turns out, Lester was working. "Little did the kid of 7 years old know she was going to grow up to marry the science adviser to Captain Video!" The arms fly into a raised V, palms up. "It would have blown my mind!" A Long Island physician's daughter born with achondroplasia (which retards skeletal development), "I've always had an active imagination" and an appetite for prose. "But then I went to school and read 'Silas Marner' and then I was going to stop reading."

Still, she ended up an English major at Hunter College in Manhattan. "Me," intrudes Lester, "I'm a happy little moron who deliberately and pleasurably dropped out of college because I didn't think it was worth a damn. And I was right!" Judy bends, whispers to Urban. Lester bristles: "Why don't you stop talking that way--he knows how daddy feels." She specialized in Joyce. Why? "Jeez, who remembers?" The word play, an encouraging professor, and by her senior year she was editing a scholarly book on Joyce titled "The Celtic Bull."

"That was how I started collecting bulls." Soon she was getting them as gifts--whence the three papals. And woe to him who calls them, uh . . . "They're NOT TOYS!" Judy screeches. Asimov found out: "Once at a party over there I just wanted to see what would happen if I quietly picked one up and put it in my jacket pocket. I don't know what magic she had, but she knew instantly. She came up to me and said, 'You give him back!' I had the distinct impression that I would be torn limb from limb." Another time he casually changed the channel on the TV. "Judy made me change it back--Urban was watching the ball game."

Well, if not toys or surrogate kids ("I decided at the age of 5 I didn't ever want children--unless they could start right away at 18"), then what? "There are certain things you don't explain," she says. "They just grew and took on their own personalities as people entered our fantasy world with us." A long recriminatory pause. "How does that sound? Am I gonna get committed?"

After graduation and a depressing six-month job hunt, the college got her an interview with Frederik Pohl, editor of Galaxy, the s-f magazine. It hardly seemed promising: "He wanted somebody to make coffee and read proofs. And it was down in the bowels of Manhattan. I mean, I didn't know there was anything south of Penn Station!" Reluctantly, she took it.

And stayed for eight years, becoming the editor, making the connections that would later make Del Rey Books a powerhouse. One long-time friend believes that her size may have influenced the decision: S-f buffs thrive on idiosyncracies, and "the minute she found science fiction, she suddenly found the people very accepting. It was like she came home." Lester met her at Galaxy on April Fool's Day of 1966. He had signed on as assistant editor, and "we'd see each other." Shortly thereafter, "my wife, who was a friend of hers, got killed in an automobile accident. Judy, at the side of the table, is whispering to Urban: "You knew daddy was married before!" And then she laid her cap for me. She says I snagged her in a moment of weakness."

"Did not! Did not!" Judy mimes a piercing schoolyard sing-song. "I had to find a father for my calves."

By the late '60s, despite her growing clout at Galaxy, "I was bored," she says, "because all the big shots thought they knew what they were doing. I had to make life interesting," and practical jokes abounded. Asimov was targeted for torment: bogus magazine covers with his name misspelled; a vicious fake review of one of his TV shows; and in 1970, a sham elopement with his editor. The ultimate prank, scheduled for her own wedding, was aborted. "We didn't think my poor mother's heart could stand it. When the rabbi said, do you take blah blah blah, I was gonna say, 'No--we staged it all for Asimov!' He would have died. But I couldn't do that to my parents."

The launch window out of Galaxy appeared when Judy-Lynn, through Lester's agent, Scott Meredith, got the rights to Clarke's "Rendezvous With Rama." She brought it over to Ballantine and said, in effect, "take the galleys, take me." In 1973 they did. At first she traveled constantly, glad-handing booksellers, drumming up movie tie-ins. For a person sick of gawking strangers, and to whom normal-sized furniture is an inconvenience, such a job demands no small courage. "She affects a kind of New York hip toughness," says Silverberg, "that kind of jumpy, cigar-in-the-mouth style. But under that is a real kind of toughness that I suppose you need when you're 3 feet and 9 inches tall." Asimov says, "she has what I call Mickey Rooney Syndrome: You're short, so act tall. That overcompensation is one of the reasons she's such a success." Although it can't protect her from aggravation: A friend recalls one prominent author "who had a habit of squatting down--actually crouching--to talk to her eye-to-eye. Later, she told me how much she hated that."

In 1975, when Ballantine president Ron Busch (now head of Pocket Books) became interested in publishing fantasy, Judy got him to hire Lester. "If you want to call it nepotism, call it nepotism." For Lester, who says "I consider myself now, by my own choice, a has-been writer," it was a rebirth. As their list grew more successful, Busch decided they needed an imprint "to break science fiction out of its category status." Del Rey Books, with Judy at the controls, was launched in March of 1977. It would prove an amazing year. In April, they published a fantasy novel called "The Sword of Shannara" by an unknown named Terry Brooks. "Booksellers didn't want fantasy," says Lester, "but it was a perfect case of serendipity. I knew I could tie it into the Tolkien stuff." The novel was a flash hit. "It was the first fiction book to hit The New York Times trade-paperback best-seller list in fiction," says Judy-Lynn. "It started at No. 5." "No, no," Lester shoots back, "it started at No. 2." Another squabble flares, subsides.

In May came "Star Wars," Judy's first mega-miracle. Before it was filmed, she got the script and preproduction artwork. "I enjoyed the story, but it was very linear. But when I saw the paintings, I said if this is what it's gonna look like, I want a piece!" She told the filmmakers to come up with a novel, and "we bought that for no money--I mean, who had heard of these Lucas people?" It sold modestly, and no one expected much--until Judy-Lynn received some slides from the production in progress. "I went into the art department to use the light box. Ron Busch was in there yelling at the art director. I put 'em on the box, and pretty soon I'm jumping up and down, yelling and screaming 'We're gonna make millions!' " She is bouncing all over her chair in recollection, little arms windmilling over her head.

"Busch looked at me and said, 'Kid, go play in traffic. The adults are working.' I said, 'Ron you're gonna regret that--we're gonna make zillions!' " Then Time magazine called it the best movie of the year; and millions of books, calendars and spin-offs later, Luke, Darth & Co. had broken records across the nation and Del Rey Books had broken into the big time. (No wonder her totems are tiny figures of ferocious power.) "Usually to make an imprint grow, it takes a while before anyone knows you're alive," she says. "But right away we had two national best-sellers, and everybody was suddenly saying, 'What is this Del Rey Books?' We were a force to contend with."

And The Force is with them, Lester says. If the American psyche is ravenous right now for Supermen, Star Warriors, Road Warriors or almost any hero who prevails in the last reel, "that's part of our success. Judy and I have gotten back to the old type of writing. Science fiction today, more than any other literature, is asserting the ancient values." ("Yeah," Judy murmurs, "motherhood, flag, bulls.") "Such ridiculous notions as that courage is better than cowardice, that a man should stand on his own two feet, that it's better to stand up and win than to lose. Kids are desperate for those ideas--they haven't been getting them."

And the del Reys are desperately busy. For one thing, they're planning a bar mitzvah for the bulls. "Our social life is 85 percent business-related," Judy says, and a horde of the publishing haute monde is coming--many of them straining their crania to imagine the proper gifts. And Judy is fretting: "I've already heard Urban practicing--'Today, I am a man.' I said, 'Urban, it needs work!' "

For another, she's about to publish what may be the biggest gamble of her career: "The Silent Gondoliers," a slender tale set in Venice and coyly attributed to the pseudonymous "S. Morgenstern, Author of 'The Princess Bride.' " The latter--"one of my all-time favorite books"--is William Goldman's comic medieval fable first published in 1973 and never a real success. "Gondoliers," the sort of gently ironic, sentimental fairy tale habitually described as "charming," has even less obvious market appeal. Worse yet, "it's not science fiction and it's not fantasy. So I'm pacing up and down, wondering how I can publish it. Finally I said to Lester, 'If you got an imprint, you gotta have a toy.' He said, 'So go to FAO Schwarz.' " Instead, "we created a whole new category: the fanciful novel." Too mushy for Lester. He mutters, "Some people think it belongs to that even more ancient category--failures."

"It's one of those crapshoots," she says. "It's possible I'm all wrong and I'm gonna have egg fu yong on my face. And I do not take rejection well. It's a great responsibility because my credibility is so high that if I tell them to put out the book, they do it. The most important thing in this industry is your credibility." So what will happen if it flops?

She looks up, blinking at the sheer inanity of the question. "Nothing. Hey, I'm a baby mogul!"