BOOK REVIEW : Serving Up a Vivid Repast of Family Tensions : THE DAY <i> by Douglas Hobbie</i> ; Henry Holt $22, 241 pages

Dinner parties are a great novelistic device. There is no better way to bring together characters of all shapes and sizes, to explore conflicts between people who would normally avoid each other and to create comic set pieces unthinkable in less awkward situations.

Douglas Hobbie has created an occasion to remember in his new novel, “The Day,” which takes place during a New England family’s Thanksgiving gathering.

At first glance, everything seems perfect in the extended Wells clan: Vigorously retired Pat and Curly are down from Cape Cod for the holiday; daughter Penny is hosting the meal with her husband, Peter, and their three kids; and younger sister Gwen is driving up with her husband, Jack Fletcher, and their two children.

But, naturally, there are a few cracks in the facade. The oldest Wells daughter, Clare, is missing, and although she hadn’t been at one of these reunions in more than 10 years, this one is different: It marks the first anniversary of Clare’s suicide in San Francisco.

Our guide to the festivities is Jack Fletcher, who, although part of the family for 15 years, is still something of an outsider. The story is told in the third person, but it sticks closely to Jack’s point of view.

Hobbie uncovers the hidden workings of a whole family by taking us deep inside the psyche of one character, whom we get to know through a complex, allusive prose style that brings us right inside his or her mind.

Whatever else he thinks about, Jack keeps circling back to Clare, who was his lover for a brief time many years ago. Clare was a nonconformist, rebelling against her middle-class upbringing through political activism. No one wants to talk about Clare’s death, having written her off years earlier.

As the day progresses, we see the family preparing dinner, eating, playing an impromptu soccer game and chatting in various combinations. Hobbie captures the prickly intergenerational conflicts in a brilliant dinner table conversation; the family tells jokes, gossips and discusses current events. Whenever Penny or one of the teen-agers says something that might be termed liberal, Peter mocks them and Gram tries to shut them up:

“ ‘Can you believe Bush going ahead with . . . SDI . . . ‘ Gwen said, ‘while one out of five kids in the country is hungry, can’t read. . . .’

“ ‘Sad dumb initiative,’ said Mary.

“ ‘Hey, Dad, isn’t it amazing that these girls know better than the whole damn world what’s good for us? The high and mighty leaders of the whole damn world aren’t as clever as they are, how did that happen?’ Peter said.

“ ‘Don’t make me throw up my Thanksgiving. . . .’

“ ‘Mary,’ said her grandmother, ‘I don’t think your father deserves to be talked to like that. You young people are too smart by half. Penny, everything is lovely,’ she added emphatically.”

Jack’s political beliefs are leftish, and he thinks of himself as smarter, more insightful than the others. They tease him for reading books that no one’s ever heard of and for avoiding shopping malls because “he thinks stupidity is contagious.”

But Jack doesn’t realize that, wrapped up as he is in his own problems, he misses a lot. At the end of the book, Gwen asks Jack why he kept disappearing all day, and we realize that while he was sitting in the back yard or walking in the woods reminiscing about Clare, he was ignoring his family.

Although he thought Clare’s absence was the subtext of the whole day, he learns that the others had more immediate things on their minds, things he had been too self-absorbed to notice: Gwen found out that her father has cancer and that Penny had left Peter for five days. Jack looks back on the day, and everything seems subtly altered: “He had been present and not present, in a manner of speaking, so that now Thanksgiving at Penny’s consisted of the day and the day he had missed.” As he did in his first novel, “Boomfell,” Hobbie has created a subtle exploration of family as seen through the eyes of a vaguely dissatisfied, intellectual middle-aged man. His writing is intense and witty, and his scenes of family tension are so precise I found myself ducking for cover. Thanksgiving will never be the same.