EARLY IN D.M. Thomas' Ararat, a middle-aged

writer describes himself as a sprinter who 10 years ago began running long distances: "In my third marathon I came in first, yet it wasn't very satisfying. It made me realize, all the more, I'm really a sprinter. I shall run one more marathon--possibly 10,000 meters--then go back to the sprints." One irresistibly relates all this to Thomas himself, a "sprinter" (poet) whose third "marathon," The White Hotel, made him famous. The final extended run, by this reckoning, would be Ararat itself. Since Thomas performs well at all distances, it would be too bad if his remarkable novel was indeed a valedictory to fiction.

If I have overinterpreted the passage, it is because this small, dense book all but insists on a reader's ingenuity, insists not on observation but on active collaboration. The novel, a technical tour de force, is, among other things, a conundrum, a puzzle to be solved. It is not recommended for hammock browsing on a lazy spring afternoon but will appeal, rather, to readers attracted to the challenges posed by, say, Vladimir Nabokov's Pale Fire, Thomas Pynchon's The Crying of Lot 49, Italo Calvino's If on a winter's night a traveller or, indeed, by The White Hotel.

An improvisation on the theme of improvisations, Ararat resembles one of those Matryoshka toys one finds in Russia, in which ever smaller dolls are nestled within dolls within dolls, though in Thomas' novel we find artists within artists within artists. "Sergei Rozanov had made an unnecessary journey from Moscow to Gorky, simply in order to sleep with a young blind woman," the book begins. Since the woman, Olga, turns out to be not so young as he thought, the middle-aged poet sits up all night improvising for her on the idea of three writers thrown together by chance who themselves create improvisations on a common theme. Their subject is Ararat, the mountain on the Armenian-Turkish border that is said to be the final resting place of Noah's ark--and, appropriately, as Rozanov talks through the night a heavy rain beats against the window.

His first narrator tells about a poet, Surkov, "the Kremlin's tame liberal," an aging Don Juan ravaged by fever and depression who sails to New York on his way to Armenia. The narrator is himself a Russian poet. Rozanov's second raconteur, an Armenian, also tells about Surkov, who this time flies to New York, where he visits a sculptor named Donna Zarifian, whose work includes a piece called Ararat. The short final narrative, by an American, is about a novelist, Mariam Toumanian, who travels from the United States to see Ararat and who, during brutal lovemaking with a "Turk," experiences passion for the first time. The novel ends back in the rain-lashed hotel room, where Rozanov and Olga comment on these stories.

What I have provided is the barest of outlines for what is actually a richly textured work. Given the covey of writers involved it is not surprising that the book is very literary--thickly allusive and filled with poetry, by Blok, Pushkin, the Armenian Nareg, and Thomas himself. Ararat, in fact, resembles a poetic sequence in that the various parts are joined together by an intricate network of symbols, motifs, and images. Details or characters introduced in one section are repeated, with variations and modulations, in other sections, often more than once. It is left to the reader to identify the relationships and to interpret their meanings. Some of the linkages are obvious, as when Surkov sees the movie Klute in the company of Anna Polanski, a teen-ager he has just deflowered, while many pages later he sees another menacing film, Macbeth, directed by a seducer of young girls named . . . Polanski. Other repeated images, including all those involving the fusion of erotic love and violence, are more complex--and more disturbing.

The absorbing first improvisation, longer than the others combined, constitutes the heart of the book. (The middle narrative, chronicling the poet's flight, press conference, and meeting with the sculptor, is a letdown. The intensity is recovered, at least partially, in the concluding section.) The opening narrative is dominated by two extraordinary characters--Surkov, quite obviously modeled on Yevgeni Yevtushenko (whose poetry Thomas has translated), and Finn, an old man "involved in international politics," who has participated in the extermination of Jews, gypsies, and Armenians. Like an ancient mariner, Finn tells his appalling story ("I was ordered to open the mother's belly with a knife, take out the baby, and throw it in the ditch . . .") to anyone who will listen.

Thomas can be deadly: Finn, after describing his part in the rape and mass murder of small children, expresses his distaste for "bad language" in literature and calls smoking "a dreadful addiction." He represents a bizarre variation on Rozanov's Armenian grandfather, who, "having in his youth witnessed an atrocity and developed a stammer, cured it by roaming the remote regions of Armenia, telling stories at isolated villages. He had perished, alongside the poets Varoujan and Siamanto, in the genocide of 1915." The attempt to wipe out the people of Armenia, a flood with many victims, serves as the central theme of this chilling novel.

Some of the book's descriptions of sadistic behavior will inevitably remind readers of horrifying passages in Jerzy Kosinski's The Painted Bird. Like Kosinski, coincidentally, Thomas has been charged with borrowing others' work, both in the Holocaust passages of The White Hotel and in his recently published translations of Pushkin. He has responded to these attacks with anger, and he seems to allude to his critics, in a more subdued fashion, several times in this novel. During the press conference, for example, Surkov is asked about evidence that Sholokhov "stole" most of And Quiet Flows the Don. "All art," he answers, "is a collaboration, a translation if you like. But plagiarism is a different matter."

Another character, in one of the few radiant moments in a book whose emotional climate is as bleak as a Moscow winter, speaks of "the rapture of silence and inspiration." Whatever the origins of this ingenious work-- and Thomas gives the source of certain details relating to the Armenian massacres and diaspora--it is clearly a product of silence and inspiration. But to say so is to raise questions about the ultimate source of the inspiration. Who, after all, or what is manipulating this lavishly gifted artist, who in his turn is creating artists who are creating artists who . . . It's something to brood about, not during a sprint, but for 10,000 meters or so.