"THE WHOLE PROCESS of writing is rewriting," contends John Gregory Dunne. Working simultaneously on a new novel. The Red White and Blue and the screenplay for a movie based on his earlier work. Vegas. Dunne views the creation of fiction as organic. People and plot grow together: "The situations is worthless without a character, and the character is worthless without a situation: asking which came first is the chicken or the egg question."

True to his words, Dutch Shea, Jr. focuses on several provocative characters entangled in a malevolent fate. The Travel's namesake, an assimilated Irish Catholic detective, finds himself constantly having to defend arsonists and murderers, partially because his lather, also a lawyer, committed suicide after being convicted of a white-collar crime. Slowly sinking in a quagmire of guilt and despair. She a still finds time to draw some colorful characters into his world.

We meet his girlfriend, the judge, who wears a .38 on the bench and at the age of 36 insists on living at home with her over-protective father, Lee, his beautiful ex-wife, also remains a force in Shea's life, especially since she alone was present when their adopted and much loved daughter. Cat, was killed by a terrorist's bomb.

The sins of the father are visited on the son: Shea, Jr. gets involved in the same sort of shady dealing that did in Shea, Sr., and the violent crimes of the client return to haunt the lawyer. Through the convoluted plot, threads weave and re-weave until every action seems to touch every character, from poor Shea to Harriet Dawson, a sympathetic child-murderer. Fate hangs over everyone's life like the faith the protagonist constantly tries to deny.

THIS SHOULD BE a depressing book: it certainly is not light humor, but irony keeps the plot humorous while Dunne's wonderful handling of colloquial dialogue makes even the most unsavory character somewhat likeable. One woman defends her husband, a heroine addict and convicted burglar:

"He in a drug program, he wouldn't do no hundred burglaries."

"I see."

"He shoots all day to relieves his disappointments."

"Of course."

"The judge give Hary a chance, he could function in society properly."

"Well said."

"His lawyer tell him to say that."

"I'm his lawyer."

"That was you tell him that shit?"

"Right."

"No shit. No wonder [he] got you."

At times, this novel reads like one of Dashiel Hammett's hard-boiled detective novels, with violent action, illicit sex and a tender-hearted toughie for its hero. But Dunne's treatment of these people remains too sensitive and perceptive for this book to be classified in that genre. As the voice shifts from omniscient narration to eavesdrop on Shea's thoughts and colorful dialogue. Dunne makes us painfully aware of his hero's growing depression as he begins to believe that he is trapped--by what his girlfriend labels the self-fulfilling prophecies of despair and his priest would call the wrath of a vengeful God.

Whatever it is that envelops Shea, the magic of Dunne's clean, almost crisp, prose captures the reader. This book ends much too quickly.

FOR HIS OWN LEISURE reading Dunne claims to read very little contemporary fiction, although he enjoys studying the works of other authors to discern their techniques: "I read a lot of books." For pleasure, the Connecticut-based author re-reads Graham Greene and Evelyn Waugh: "But most specifically and definitely not Brideshead. It's a sumptuous bore. "However, he has nothing but praise for fellow fiction author John Updike and his latest, Rabbit is Rich.

Married to Joan Didion, author of The White Album and A Book of Common Prayer among others. Dunne has easy access to critical input. Although the two have dramatically different styles, Dunne and Didion work together, reading and advising each other's works-in-progress. The couple is currently collaborating on the screenplay for Vegas, having done four motion pictures together previously, including the film version of her novel Play It As It Lays. Their most recent joint effort, True Confessions, based on his book of the same name, starred Robert Duvall and Robert DeNiro as brothers, one a priest, the other a police officer. DeNiro, working on Raging Bull when True Confessions was being cast, accepted the lead after 13 other actors refused it. Dunne, however, professes great satisfaction with the movie, and refers to DeNiro affectionately as "Bobby."

Although no plans for filming Dutch Shea, Jr. loom on the immediate horizon, such an action-filled novel would appear a good basis for a detective film. But while Dunne obviously enjoys working on screenplays, he worries that his novels lose much in the transition from print to film. The process involves boiling a 300-plus page novel down to about 120 pages for almost two hours of film: to do this the author must simplify plot lines, remove minor characters and trust in his actors' abilities to convey the emotions written into the novel. The result may be radically different from the original prose work. And yet Dunne shows no signs of abandoning the silver screen or slackening his work at the typewriter. With a critically well-received movie like True Confessions and a needle-sharp novel like Dutch Shea, Jr. to his credit, we should hope he never will.