What Is Dad Trying to Tell Us? : THE PRISONER’S DILEMMA<i> by Richard Powers (Beech Tree Books/William Morrow: $17.95; 352 pp.) </i>

If the world is irremediably crooked, an irremediably straight man must end up cracked.

That is heroism, perhaps; but what about the children? How am I to live? is the implicit question they put to their parents; and a parent destroyed even in a good cause has given an answer so terrible as to approach betrayal. Can his children understand him, first of all; and then forgive him? Can they understand and forgive themselves?

It is the central question in “The Prisoner’s Dilemma.” Richard Powers’ searching, oddly constructed novel takes a theme that recurs incessantly in modern American writing--Where are you, Pop?--and worries it down to the bone. Too far for its own good, despite the passion and wit with which it is done. Fictional art lies less in exposing the bones than in making them dance, clothed in a little flesh.

“The Prisoner’s Dilemma” has a three-fold structure; or perhaps we should say that it consists of three separate levels of narration so closely linked as to bleed into each other.

The main one, in length, detail and fictional completeness, is the story of the Hobson family. The father, Eddie Hobson, is brilliant, passionate, evasive and ill. He is a high school history teacher who has restlessly moved his family from place to place until they have ended up in DeKalb, Ill. The town is a symbol of mid-American normality, and it is the home of the inventors of barbed wire.

That tells us a lot. Hobson’s America is normal and lacerating. An idealist, a non-stop verbalizer, a fount of quips, riddles and gnomic pronouncements, his passion for history is a faith in salvation through understanding. What he must try to understand is the laceration.

Hobson suffers from radiation sickness that has produced a slow but fatal cancer; the illness was contracted when he was stationed as an Air Force mechanic near Alamogordo during the testing of the first atomic bomb.

To a man who requires meaning in history, it is a mortal affront, more to the spirit than to the body. Hence the evasion. Eddie Hobson’s wife and his four children have been captivated by his scintillating mind-play. Their true captivity has come from his refusal to acknowledge or name his illness.

“Your father is not well,” was the formula that governed their lives as they grew up, changed homes--as alternate collapses and remissions got Hobson out of one job and into another--and above all, took part in a jokey family conspiracy that devised witty formulas for everything except for what was really happening.

The Hobson segments of the book are told with skill and compassion. The portrait of a family loving and struggling with a father who is a damaged prestidigitator is a familiar one, but Powers has his own fresh portraits and observations.

The four children are movingly rendered, each in his or her own mix of evasion and efforts to overcome it. They advance and retreat in their confrontations with each other and, in a unity that continually comes unstuck, with Hobson. He finally submits to going to the hospital, escapes, comes back and dies.

Life at the Hobsons is funny, disturbing, stagnant and hopeful by turns. There are times when the reader may feel too closely wound in the web of family pieties, jokes and warning signals. They are beautifully told, though. And if Hobson himself must necessarily oppress us as much as he does his family, there are moments of clarity and force when we see him in the affecting light of his own doomed, absurd and righteous struggle.

The other two levels on which Powers has chosen to tell his story are designed to elevate the particularities of the Hobsons into something more universal. In different ways and to different degrees, they both fail.

One of these levels consists of a fantasy that Hobson devises and dictates on a series of tapes. Intercut in italics throughout the book, they are an allegory on American culture and history. Starting with the World’s Fair of 1939, with its brash message of eternal progress through technology, it turns into a parable whose hero is Walt Disney as a frustrated prophet of the innocent and generous side of American life.

Disney, in Hobson’s vision, single-handedly fights the incarceration of the Japanese-American population during World War II by convincing the authorities to release 10,000 of them in exchange for his production of a great epic--some of the Nisei will work on it--that will explore abiding American values and raise domestic morale.

The episodes are hazy and confusing. Perhaps they are intended to illustrate the fuzziness as well as the idealism of Hobson. After a while, though, they become increasingly exasperating and virtually unreadable.

The third level of narration, also intercut in italics, is much better done but considerably more puzzling. Powers tells of his own father--or of a figure presented as his own father--as a kind of intended counterpoint to his story of the Hobsons.

It is affecting and well written. In a scene at the start, the elder Powers lies on the grass at night explaining the constellations to his children, who “distribute ourselves over his enormous body like so many spare handkerchiefs.” That is a lovely image.

But the author’s story of his own family is almost indistinguishable from his story of the Hobsons. His father also is an itinerant and brilliant history teacher, also a man of evasions, also a creator of aphorisms and riddles that weave a cloudy web over his mystery. And the mystery, it turns out, is Hobson’s: jaundice and cancer induced by radiation sickness.

This is not really counterpoint. It is more like the device that harmony teachers tell us to avoid: parallel thirds. They do not enhance the theme, we were instructed, they shadow it and drag it down.

Powers’ telling the story in two marginally different modes makes “The Prisoner’s Dilemma” an experiment of some boldness, but it doesn’t work. Instead of resonance, it produces a curious and enervating echo.