Alter Ego : BIOGRAPHY, <i> By Celia Gittelson (Alfred A. Knopf: $19; 261 pp.)</i>

Though you might expect the focus of this piquant novel to center upon the roistering, flamboyant biographee, the real hero is the reclusive biographer, a mild and timid fellow named Raphael Alter. His preliminary research accomplished, Alter has placed the traditional request in the New York Times Book Review, asking anyone who knew or worked with the poet Maxwell Leibert to write to him.

The response is immediate, if not altogether gratifying. The mailbag includes a whining essay from a failed academic who offers a trivial anecdote; a genuinely pathetic letter from a liquor-store owner stiffed by the hard-drinking Leibert and now desperately in need of the money; a blurry Xerox of a Leibert poem written on a place mat at a Poughkeepsie diner and retrieved by the waitress, and also a package containing a broken pair of the poet’s spectacles left at a friend’s house during World War I. Conscientiously, Alter follows each of these leads to their respective dead ends, a task that frustrates him but entertains us.

The simple but elegant device of the Times’ query not only introduces us to a cast of diverting secondary characters who are perfect showcases for the author’s satiric touch, but also, by refraction, provides us with insights into the personalities of the self-centered Leibert and the kindly but bumbling Alter.

Unlike his celebrated subject, who racketed around the country teaching, boozing, reading his poems and seducing his admirers, Alter leads a life of dreary circumspection. He lives in a shabby apartment in the decaying tenement house he inherited from his father, functioning not only as owner but manager. Instead of supplementing his meager income as the legacy was meant to do, the building is an open vein, draining Alter’s creative vitality, consuming his limited resources and distracting him from his literary work.

Hobbled by rent control, unable to afford the necessary repairs, he creeps around his sorry domain hoping to elude his elderly, frantic tenants, but failing--a situation that allows us to meet the entire picturesque lot and to see Alter wearing his ill-fitting landlord’s hat. “I’m running a death trap here,” he thinks, but he has no choice but to continue writing in the morning and dealing with leaky ceilings and clogged plumbing in the afternoon. By the end of a typical day with Alter, only a masochist would yearn for a literary life eased by private income.

In addition to the inevitable bills, reminders from his dentist, appeals for alms and invitations to appear pro-bono at remote writers’ workshops, the next mail contains an alluring surprise: an unsigned, stiffly written letter offering “information regarding Maxwell Leibert that I believe may be of interest to you. There is no doubt in my mind that his life story cannot be called complete, or accurate, without it.” The writer promises to meet Alter if he will suggest a time and place. Optimistically, Alter hopes his informant will be a woman. He hardly knows any, and his circumstances are hardly likely to bring attractive specimens into his orbit. Though still young, he’s settled into the sad, fussy routines of an aging bachelor, though not without wistful regrets.

Diligent as always, he responds to his latest and most quixotic correspondent, and is rewarded by a call from a “buttery, scorched” female voice, a sound that awakens “a sensual memory of rice pudding fresh from his mother’s oven with a rusty cinnamon top. His spoon, as it were, pierced the lightly burnt shell and sank slowly, slowly, into the warm gooey heart of the dessert.” The owner of the rice-pudding voice turns out to be an auburn-haired beauty somewhere in her middle 30s, exactly the sort of apparition who occasionally swims into Alter’s celibate dreams. The interview slips out of Alter’s control, as the mysterious Chloe questions him, clearly trying to decide if he’s a suitable receptacle for her crucial information.

Apparently he passes the preliminary inspection, because by the end of that first meeting Alter has learned that Chloe worked as Max Leibert’s gardener while she was a student at Bennington College and he was poet-in-residence. That, however, is all he discovers, though he deduces from Chloe’s references to her employer as “Max” that the connection may have involved more than mere landscaping. Having provided him with this provocative snippet of information, Chloe leaves abruptly, promising to call after she’s had time for further thought. By then Raphael Alter is in love, his interest in Maxwell Leibert subsumed by his feelings for Chloe.

The crucial encounter with Chloe is exquisitely timed, leaving four-fifths of the book for the gradual, almost miraculous transformation of Raphael Alter from a wan spectator at the feast of life to an enthusiastic participant in all its anguish and delight. The connection between the monkish biographer and the hearty sensualist who is his subject, which at first seemed a mismatch made in an editorial boardroom, turns out to be a true communion of soul mates, ordained by fate and destined to be supremely successful. Along the way, we learn the astonishing, unflattering, but still affecting truth about Maxwell Leibert.

These revelations lend “‘Biography” the suspense of a detective story while not detracting in the least from a book that is essentially a witty and cerebral romance.