By Hugh Nissenson

Sourcebooks Landmark. 308 pp. $18

First, some caveats. If you are a reader who thinks a novel should be entertaining, a distraction, something to get your mind off the human condition, "The Days of Awe" isn't for you. If you scare easily, if you're already in some despair -- about the way the war is going, about New Orleans -- I'd think twice about picking this up. If you're bothered by a greater-than-average fear of death, I'd take the prudent path and pass on this book.

If, on the other hand, you believe that at their best, novels should be transformative, should rip the dusty curtains from our everyday vision and reveal the reality of our existence; if you don't mind being terrorized by a narrative if it takes you to a greater understanding of what it means to be alive on this earth; if you're willing to take this ride with Hugh Nissenson, then you're not in for a treat exactly -- that would be the wrong word -- but you'll be looking at a different world when you finish his pages. A last warning: Read it in the daytime if you can. All the special effects of all the Hollywood horror movies disappear into nothing compared with this book.

The plot absolutely cannot be given away, but a little about the characters and the place and time in which they live may suggest some of the story. The place is Manhattan; the time, Aug. 1 to Nov. 28, 2001. (So this is a 9/11 story, but not really, not completely.) The characters are Artie Rubin, who writes popular histories of the old mythological gods, and Johanna, his wife, who makes the real money in the family as a stockbroker. They're in their late sixties, where, whether we like it or not, most of us will have finished the significant work of our lives and will find ourselves waiting for death or grandchildren, whichever comes first.

Artie and Johanna have reason to be optimistic: Their daughter, Leslie, is pregnant for the first time. (Artie and Johanna are secular Jews who live on Manhattan's Upper West Side. Leslie is married to Chris, a personable and very decent Christian. Their marriage seems to be working out all right. But Chris comes with a host of gentile relatives, which puts both families a little bit at odds. If the baby is a boy, for instance, will he be circumcised? Chris says no.) Against these future-oriented concerns, Artie and Johanna have some troubling health problems: high blood pressure and other ailments. Their dear, lifelong friends are dimming out: This one has a melanoma, that one a heart bypass, another is advancing rapidly into Alzheimer's. But what is there to do about any of that? Walk the dog, make doctor's appointments, give dinner parties, pass the days in work.

Artie finds himself obsessed with Odin, the Norse god of war, who died and came back with an awful knowledge. The awful knowledge the reader has here is what will happen on Sept. 11, but of course the characters know nothing -- how could they? As the "dogs go on with their doggy life," as W.H. Auden writes in his poem about Icarus, the humans here must go on being human. They live in New York, and their lives are narrow, claustrophobic, dreadfully circumscribed. Breakfast, walk that dog, work, once-a-week sex, sleep, wake, walk that dog.

A crucial subplot here involves Sutton, Chris's brother, a believing Christian (not a fundamentalist, just a regular churchgoer), who's going out with a girl who two-times him with his boss. Their one sex scene is as rude and vulgar as a slap in the face. Can't they be more lofty and romantic in view of what's coming? Of course, they don't know what's coming. But they work in the twin towers.

Artie and Johanna's synagogue is tuning up for Rosh Hashanah and then Yom Kippur, holidays when even the most secular Jews tend to show up to celebrate their heritage. "The Days of Awe" falls between these two occasions. "Religious Jews believe God decides during this time who'll live and who'll die in the coming year," Artie tells his son-in-law. "They confess and repent their sins in hopes of being spared. Johanna and I live in a world from which there's no appeal." By this time the towers have already fallen. Death, destruction, misery, fire, sorrow. But the towers are only paragraphs here in the long book of life. Man and woman are born to die. And there may or may not be a god to appeal to, unless it is Odin, with his fury, his awful knowledge.

The deaths in the towers are hardly even the point here, except that they press upon the characters the awful fact of extinction and the possibility that there is no appeal, no help for any of it. At just this point is where people fall away from faith in disgust and despair, or, just as desperately, cling to it as a drowning man might cling to a splinter in the stormiest ocean.

One person falls gravely ill during this period. Another loses his or her mind, making increasingly crazy bargains with a god who may or may not be in residence in whatever heaven; who may or may not give a fig about all that we suffer here on earth.

Meanwhile, a baby is coming. The dog needs to be not only walked but shampooed. The housekeeper, elderly and infirm, leaves pools of old salad dressing in the back of the refrigerator.

How does all of this sound to you? Does it make you want to buy the book? Or would you rather watch hours of CNN where death comes in puffs of smoke and there's hardly any crying, except on "their" side? Or maybe "CSI," where the criminals are caught in 48 minutes, no exceptions? Would you rather read about breakthroughs in cancer research, where the implication is: If we just tried hard enough, we could live forever? Would you rather live as if "God's in His Heaven -- all's right with the world?" It's up to you. The best art hurts. It's excruciating. If you crave it, take a look at "The Days of Awe."

Sunday in Book World

* How Abraham Lincoln's depression drove his greatness

* Caryl Phillips's powerful novel about America's first black superstar

* Joan Didion's devastating "The Year of Magical Thinking"

* Larry Moffi on the perilous mix of sex, drugs and sports

* Terry Pratchett's ingenious, brilliant and hilarious "Thud!"