By Thomas Palmer

Ticknor & Fields. 308 pp. $19.95

IT'S HARD to approach any novel about the nature of reality without a certain sinking feeling: Apart from the fact that Kafka always turns out to have done it better, novelists who busy themselves questioning the existence of matter tend not to be overly concerned with such niceties as plot and character. So innocent readers who were looking for nothing more than a rousing good story are forced instead to wade through a sea of minimalist angst.

To give Thomas Palmer his due, such is not the case with Dream Science; far from being a minimalist work, its protagonist's reality-testings are described, at least at first, in the robust fashion of an adventure story. It's just that, in this case, the adventure happens to be crossing from one world to another.

Rockland Poole, a stolid yuppie businessman, finds himself stuck in a windowless office, from which he can find no exit, for 17 long weeks. Tended by a surly and violent man who seems to come and go as he likes but will not help his captive escape, Poole is alarmed first at his imprisonment and later at how little he truly misses his wife and daughter and whole previous existence: "What he felt was that he had never been freer in his life."

Finally, his keeper grows friendly enough to explain to Poole that what has happened is that he has inadvertently stepped over a "line" -- a demarcation between the world of the living and the not-quite-dead -- and that he is under observation by a mysterious research society concerned with the alarming significance of his crossover. Poole then manages, with his keeper's help, to find a line and reenter his former life, where he does not even seem to have been missed: The 17 weeks took just a moment of ordinary suburban time.

Feeling disoriented and ghostly in the world of the living -- "You are now for me a kind of dream, a dream of staying in place, of becoming a link in time," he writes to his wife, Carmen, while she sleeps in their bedroom upstairs -- Poole is half-relieved to find himself crossing another line into yet another half-world, where he finds himself a female companion and learns yet more disturbing things about the infinity of tenuous realities. This second sojourn in ghost-time is almost a negative Robinson Crusoe adventure, a melancholy return to nature.

Unfortunately, Palmer's invention seems to flag in the second half of the book, when a faulty line that Poole has accidentally conjured up in Stamford proves fatal to a large part of the town: A ferocious explosion claims vast numbers of lives and buildings. From then on, the novel degenerates into a portentously solemn rumination on the end of the world. Palmer shifts between Poole's and Carmen's points of view, with a few forays into the mind of Waxman, the somewhat tiresomely unconventional psychiatrist Poole has been consulting in his slummy arsenal of an office. The three of them huff and puff and fret endlessly about what is about to happen, how much responsibility Poole bears for the impending disaster, how they feel about his potential to destroy all of Life as We Know It, and what on earth they should do about it.

AS THE SINISTER omens mount, we are given to understand that the end of the world really is at hand here, but Palmer's characters have become so numbingly unengaging in their cogitations (except for Carmen, who retains her ordinary tenderness and through her compassion for Poole arouses some of the same feeling in the reader) that it is hard to care. And since the characters have been described only in the most cursory fashion, we can't really mourn for the loss of their lives either. In fact, the reader starts wishing that the final cataclysm would hurry up and come, if only so everyone can stop pondering it.

Perhaps it takes a Kafka to create enough tension from the mere act of thinking to keep up a narrative's momentum. Palmer is not Kafka; as the first half of Dream Science attests, however, he is a pretty accomplished novelist when he chooses to be. One can only hope he will steer away from science-fiction-like tales of other dimensions next time and concentrate on delivering the three-dimensional characters his beginning seemed to promise. In the end, ordinary reality may be enough of a challenge for any novelist. Certainly Cheever's suburban world, with all its failed connections, helpless yearnings and modest epiphanies, seems ultimately much more mysterious than that of Dream Science.

Evelyn Toynton is a New York writer and critic.