Forget Marian the Librarian. Elizabeth McCracken pursued the profession for a decade, but she'll never fit the stereotype of a stern or sedate guardian of bibliophilic decorum. An engagingly forthright young woman who takes her comic turn of mind seriously, McCracken writes books about idiosyncratic characters who find themselves in unlikely situations. Her second novel, Niagara Falls All Over Again (Forecasts, May 28), out this month from Dial Press, is the exuberant and poignant saga of a two-man comedy team whose physical appearances and personalities (the fall guy: fat and dopey; the straight man: thin and sporting a mortarboard) are only the outward manifestations of an inspired and loving companionship ultimately riven by a fundamental difference in their views of life.

Eccentric characters joined in unconventional relationships are a hallmark of McCracken's fiction. In general, they're aware of their place on the outposts of society, accustomed to loss, searching for connection and love. The tall woman married to a tiny tattoo artist who maps his wife's entire body with his art in the short story collection Here's Your Hat What's Your Hurry is one such example, as is the armless wife and mother in another tale, whose gift to her children is to make herself seem normal. McCracken's first novel, The Giant's House, is narrated by a lonely librarian in her mid-20s who befriends and then falls in love with a young boy afflicted with gigantism, despite the 15-year difference in their ages. McCracken presents all her characters with a mixture of dry wit and bemused tolerance. A characteristic tone of plangent nostalgia is leavened by snappy, tart dialogue, quirky but surprisingly apt similes (one character is "as chinless and gloomy as a clarinet," another's eyebrows are "so plucked that they looked like two columns of marching ants") and aperçus that resonate with earthy wisdom.

Beginning in the 1920s, Niagara Falls All Over Again chronicles the life of Mose Sharp, scion of a Jewish family from Valley Junction, Iowa, a suburb of Des Moines. The only boy among six sisters, Mose decides early on that he'll be stifled if he takes over his father's haberdashery. Mose and his older sister Hattie plan to run away and become stars in vaudeville, but after a stunning tragedy, Mose goes on the road alone. When pudgy comedian Rocky Carter anoints Mose as his straight man, a nerdy know-it-all called the Professor, the team of Carter and Sharp savor the heady rush of fame, first on the vaudeville circuit, then in Hollywood. The lifelong partnership is both enriching and all-consuming. It's only after he marries and has children that Mose realizes the downside of the relationship, the way Rocky's self-destructive personality threatens to rob Mose's own life of warmth and tenderness. A constant thread throughout the narrative is Mose's wonder at the miracle that a Jewish boy from Iowa (Mose's father was born Jakov Sharansky in Lithuania) could gain celebrity and wealth.

McCracken says she did not intend that Mose would be the protagonist of her narrative. She had begun a novel about the Jewish population of Des Moines, based loosely on the experiences of her mother's family. "Everyone in my family loves to tell stories," she says, recalling her delight as a child when her mother talked about her own early years. An elderly cousin was another repository of family anecdotes; it was she who showed McCracken two photos that haunted her imagination. Both were of the real Mose, a great uncle. One showed him as a young man, "in a very theatrical pose, looking beautiful, with thick black hair," McCracken remembers. The other picture captured him in his 50s, "looking broken. He's wearing an undershirt, he's bald, and he has a cigarette dangling from his mouth. He became a shopkeeper. And my cousin said to me: 'It's a shame he wasn't born into another family. He should have gone into vaudeville. He was so funny.' "

In typical fashion, McCracken acknowledges her unromantic Midwestern setting in the novel's first sentence: "This story—like most of the stories in the history of the world—begins far away from Des Moines, Iowa." Yet to McCracken, who was born in Boston and raised there and in Portland, Ore., annual visits to Des Moines made it "the constant in my childhood." Her grandmother Ruth Jacobson, a lawyer and a tireless civic activist, was a magnetic figure. Grandma spun endless reminiscences about her own grandfather, Des Moines's first ordained rabbi; his son (her father), the owner of a furniture store; and her 10 siblings, all of whom earned professional degrees. During McCracken's two years of postgraduate study at the Iowa Writers Workshop, she visited her grandmother often; Here's Your Hat is dedicated to her. Ruth Jacobson died three months after the book was published, but not before she'd had a chance to take McCracken around town and introduce her as "the youngest person ever to publish a novel." "The only thing true in that sentence is that I'm a person," McCracken says with a smile. "It was not a novel, and I wasn't even close to being the youngest. But she wanted to make sure her enthusiasm was commensurate with her pride in me."

McCracken herself relates family stories with gusto. She has a mobile and expressive face, with earnest brown eyes and heavy brows that furrow when she carefully considers a response to PW's questions. Dark brown hair curls haphazardly over her shoulders. Her full lips seem designed for pouting until they break into a grin that awakens the trace of a dimple. When she meets PW in a cafe in Manhattan, she's wearing a demure black blouse turned camp by a necklace with luridly colored medallions of old-time cartoon characters (Blondie, Skeezix, Smilin' Jack), a chic white skirt and black net stockings that would be comfortable doing the can-can. She's in town from her home in a Boston suburb to hear her agent, Henry Dunow, read from his new memoir, A Way Home. It's given her a chance to eat an Abbott and Costello sandwich at Lindy's and to buy her older brother, Harry, a nest of Russian dolls that portray a riot of Fleisher comic-book characters in diminishing sizes.

It was her brother's interest in old comic strips, radio shows and movies that awakened McCracken's self-styled "obsession with the past." The siblings watched "hundreds of films with every comedy team there was," she says. Now a computer journalist, Harry still shares her frame of reference. They're both members of a "tent" or chapter, of the international Laurel and Hardy society called Sons of the Desert. McCracken was watching a tape of the last Laurel and Hardy movie, Atoll K, when she heard Hardy utter a line that she later used for Niagara Falls's epigraph. "Haven't I always taken care of you? You're the first one I think of." The quote encapsulates Carter and Sharp's symbiotic bond. One of McCracken's last research forays for the book was a sentimental journey with her brother to L.A., where they attended a 90th birthday party for one of Harry's friends, the legendary animation designer Maurice Noble. Noble's clear memory of filmland in the 1930s and '40s provided McCracken with authentic background material. He died soon afterward.

The dedication to Niagara Falls offers a clue to McCracken's wisecracking fictional voice: "To Samuel and Natalie Jacobson McCracken/ My favorite comedy team." In explanation, McCracken says," I come from a family of tremendously eccentric people." According to McCracken, her parents are deadpan comics of memorable wit, albeit temperamentally unmatched. Her father is quiet and reserved, with an encyclopedic memory; her mother is social and outgoing. Physically, too, they are a startling contrast. Samuel McCracken, a Chaucer scholar who for three decades has been Provost John Silber's assistant at Boston University, is "6'2" or 6'3"—a really big guy." Natalie McCracken is 4'11", and she walks with two canes, the result of a birth injury. She holds a Ph.D. in theater, and is head of publications at BU. "They're a distinctive couple," McCracken says, "sort of a team of their own. You can recognize their silhouettes from blocks away."

Her parents' tolerance of their mixed-religion marriage undoubtedly influenced McCracken's eclectic view of human nature. When they visited Des Moines, McCracken's family worshiped both at the Cottage Grove Presbyterian Church and her grandmother's temple. Her ecumenical grandmother Jacobson believed to the end of her life that Easter was a secular holiday. Grandfather McCracken was a professor of classics at Drake and the editor and publisher of American Genealogy magazine. From both sides of the family, McCracken stresses, she received a strict sense of right and wrong, and a feeling of civic obligation. "A combination of guilt and moral imperatives never hurt anybody," she deadpans.

McCracken's own career path has followed parallel channels. She took a part-time job at the Newton, Mass., local library when she was 15, and stayed there seven years, through high school and college. Early on, she determined that being a librarian would be her "money job," and she earned a library science degree in 1993. Meanwhile, she devoted herself to writing fiction. Her books carry acknowledgments and thank-yous to Sue Miller, who taught McCracken creative writing at BU, and Allan Gurganus, who was her teacher at Iowa. During her first session at the Fine Arts Work Center in Provincetown, in 1990, she met Ann Patchett, who was working on The Patron Saint of Liars. She and Patchett became fast friends and first readers of each other's works. "We understand how much to say to each other," McCracken observes. "We have very similar views of fiction writing, but extremely different methods. She's very plot oriented, and I'm not so handy with plot. She writes much tighter first drafts than I do. My first drafts are horrific and inefficient; I write pages and pages that don't get into the book. She's very good at seeing the book within the book."

A tight circle of other writer friends (she thanks Karen Bender, Bruce Holbert and Max Phillips, among others) also offer advice. It was Phillips who recommended McCracken to agent Henry Dunow, during McCracken's second year at Iowa. Dunow read several of her stories over a weekend, and called her up on the following Monday. Since McCracken says she never thought ahead to possible publication, she's grateful for the benevolence of fate. "I'm appalling about the future," she says. "It's not that I lack ambition; it's that I lack forethought."

Even Here's Your Hat being the last book with the Turtle Bay imprint turned out to be lucky for McCracken. Susan Kamil went to Dial Press, where she edited The Giant's House, which was an NBA finalist in 1996 and earned McCracken a place on Granta's Best Young American Novelists list that same year, and the current novel. "She's a great editor," says McCracken of Kamil, "one of the best. She rarely says she doesn't like something in my work. She asks leading questions about my intentions, and sometimes she tells me I haven't got there yet," McCracken says. "I really need everything slapped out of my hands. I'm an endless reviser." That same focus on the present, and the past that formed it, determines the voices in her work. All are first-person narratives, whose protagonists' distinctive voices come to her easily. "I end up thinking like the character I'm writing about," she says, confessing an instinctive empathy for people on the fringes. "I think that people are more eccentric as a whole than popular culture would have you believe," she observes with the air of one who dares you to disagree. "The moment that someone reveals some strange quirk, I begin to like them a lot." McCracken's favorite book is A Confederacy of Dunces; she says that her own work is "never as funny as I want it to be." Her interest in the past also determines the structure of her fiction, because "the only way I know how to give my books resonance is by going to the backstory." In contrasting her characters' hopeful beginnings and the vicissitudes of their troubled lives, she maintains a sympathetic understanding of the resilience of the human spirit.

McCracken gave up her library job to write The Giant's House, but she went back to work there two days a week for a while after that book was published. Now she sometimes misses her former career. "As a writer, you're essentially alone, and you're necessarily the most important person in the world. That's not psychologically healthy. If you've got a family to balance it out, maybe you're not so self-absorbed. For a librarian, though, there's a fuller spectrum. People come in and say: 'I need this, or I need that'... I love the sheer randomness of it."

Appropriately, the sheer randomness of life acquires enchanting resonance in McCracken's fiction.