The dust jacket of Timequake, Kurt Vonnegut's latest (and probably last) book, promises some sort of science-fiction fantasy ride through a highly ironic universe. "Futurology!" it screams, "Ten years of deja vu all over again!" Unfortunately for Douglas Adams fans, nothing could be further from the truth. You can't really blame the poor dust jacket writer, who had the unenviable task of summarizing, in concise and entertaining prose, the essence of a book that defies easy classification.

Newcomers to the 75-year-old author's work will most likely be amused, but more confused, by the book, and even Vonnegut veterans may be caught off guard if they are expecting anything resembling a conventional story. The kind of wildly imaginative plotline that characterized his earlier and best-known satirical novels (such as the absurd, apocalyptic masterpiece, Cat's Cradle makes no appearance here. Fimequake is not so much wildly imaginative as wildly cantankerous, not so much a great read as a great rant.

The ostensible premise is that, on Feb. 13th, 2001, the universe suddenly shrinks, forcing us all to relive 10 years of experiences without changing a thing. But the plot's all just a springboard for Vonnegut's meandering, anecdotal and highly autobiographical discussion of life, death, history, religion, war, politics, family values and "the death of American eloquence" (among many, many other things).

It's almost as if Vonnegut wrote a novel, decided it was crap, then wrote a sort of disjointed memoir over it, using elements of the original book to illustrate (or simply to accompany) assorted observations and opinions.

Which is, in fact, exactly what he did. Timequake was scheduled for publication some years ago, but Vonnegut pulled the plug just before the book went to press. His reason, as he explained at the Brattle Theatre Tuesday night, was that he "didn't know what the hell it was about." Suddenly one book short of a three-book contract, Vonnegut spent the next few years overhauling the novel, drastically paring down the original "temporal anomaly" plot and filling the void with personal remembrances and ruminations.

If there are shortcomings to this method, Vonnegut is fully aware of them. Throughout the book, he freely admits that he possesses neither the patience nor the desire to create three-dimensional characters. "If you create a character," he explained at the Brattle, "he's going to use up the whole book. You'll never get to talk." He attributes his historically lukewarm critical reception to this anti-character prejudice (and to his stubborn refusal to use semicolons). Basically, he doesn't care. He wants to talk, and he wants his voice to be heard.

Not that Vonnegut's voice has ever been very difficult to discern in any of his books. His own unapologetically leftwing, anti-technology standpoint is abundantly clear in each one of his savagely ironic novels. In Timequake, though, he gives it full throttle, often ranting about modern America for chapters on end without returning to the world of Kilgore Trout, his fictitious "other self."

These ruminations are not digressions: they are the book. They come in short bursts, as if the again Vonnegut, an unrepentant smoker, is catching his breath after each little revelation.

The subject matter bounces from Hitler's last words (the Further entertains a few possibilities, including "BINGO!," before settling on "I never asked to be born in the first place") to the final moments of his first wife's existence (an event which is treated with great respect and tenderness and features some of the book's most skillful imagery). If anything is a digression, it's the barely developed timequake plot itself.

On the other hand, it obviously wasn't Vonnegut's intention to create a fine, textured novel. He speaks of Timequake not so much as an opus unto itself, but as the final chapter in a body of work that spans three decades and eighteen books, all of them still in print. He notes that, unlike the many writers of his generation, he has lived to a ripe old age. "I got to look back," he crowed at the Brattle, "And I feel lucky as hell." In the course of "looking back" through the lens of Timequake, he covers a lot of familiar ground: his trademark anti-nuclear sentiments are very much in evidence, especially at the beginning of the book, and he spends a good deal of time on World War II and the death of American socialism. As a result, the discourse often sounds very dated, an effect which is amplified by Vonnegut's deep and abiding suspicion of technology and his resulting unwillingness to give the so-called "Information Age" any serious consideration ("You're being cheated out of being alive!" he warned computer users). Even Vietnam receives only a passing mention.

Clearly, Vonnegut is generating his own customized timequake, taking his readers back in time to experience with him historical events he sees as significant-namely, events that either happened to him or somehow played a major role in his own life.

But despite its obvious preoccupation with selected ages, issues, and catastrophes, Timequake rescues itself from complete self-absorption with its anarchical and irrepressible humor-a Vonnegut trademark that has withstood both the ravages of time and countless packs of Pall Malls. By refusing to take much of anything too seriously, the book manages to avoid drowning in its own Vonnegutia or becoming The World According To Kurt (or, even worse, some sort of humanist Dianetics). Popping up all over the book, absurd little litanies such as "something the cat drug in" (what people, especially scientists, like to make each other feel like) or "a dog's breakfast" (Kilgore Trout's expression for the human brain) establish a familiarity that helps the reader adjust to the author's inexhaustible outrage at the evils of the modern world.

For all of its eccentricities, Timequake adheres to at least one Vonnegutian standby: make 'em laugh while you're showing them their Armageddon. It's not exactly a spoonful of sugar, but it does help the medicine go down.

Perhaps the most remarkable thing about Timequake is the genuine celebration of life going on beneath the rant and beyond the darkly comic bitterness. Early in the book, Vonnegut quite earnestly exhorts everyone to appreciate the sublime moments of beauty that pass unnoticed. He recalls his Uncle Alex, a Harvard-educated insurance salesman who made a point of noting such moments by saying: "This is nice. If this isn't nice, what is?" It is this uncharacteristic warmth, emerging cautiously from beneath the book's crusty exterior, which ultimately makes reading Timequake a rewarding experience.

So is this the end of the literary line for Vonnegut? "I'm 75 years old," he answered gruffly, "You can ask an insurance agent." According to the author, he will put down his pen for good and take up painting silk-screens, which he gleefully calls, "a terribly impractical process."

"I give my whole life's work a B," he concluded in his talk at the Brattle, "which is better than I ever got in college."Photo courtesy of G.P. Putnam's SonsWho's the cat who won't back out when there's rationality all about? Kurt.