John Irving’s new novel is a kind of triumph. At 800-plus pages, “Until I Find You” (Random House, $27.95, 848 pages) stands as an ur-text, published at the tail end of the output it explains. This is Mr. Irving’s self-declared fictionalized autobiography – in interviews with the New York Times, Mr. Irving has explained that “Until I Find You” was originally written in the first person. He rewrote it in the third person to make it less confessional.

The first half of the book is about sexual abuse, the second half about a search for a lost father and the re-evaluation of a mother. Mr. Irving’s fans will recognize in Jack Burns a prototypical Irving character – the version of Mr. Irving that inspired Mr. Irving’s career. He is a virtually silent boy with a special feature: in Jack’s case, irresistible prettiness; in Garp’s, compact sullenness. Jack Burns also shares with Garp a submissiveness among adults, especially among women.

These beginnings – for in Mr. Irving’s books, childhood takes only the first few hundred pages – allow characterization to start slowly, with a few signature tics. Meanwhile, the author brings a highly thematic world immediately to life.

In “Until I Find You,” that world is primarily sexual. Maritime tattoo parlors dominate the book’s opening sections, casting a salty blue pall over the rest of the book. Jack’s early sexual experiences have a predictably Coney Island flair. As a third-grader, he becomes involved with an overweight teenager. Eventually, he loses his virginity to a Portuguese kickboxer in her 40s. Set against his mother’s tattoo business, Jack’s sentimental education is, to his lasting detriment, only skin deep.

Although Mr. Irving can be a tearjerker, the violins are suppressed in this novel. But his other key, the traumatic, is in mature flower. The grail of “The World According to Garp” is Jenny Fields’s nurse’s uniform, which she wore when she nursed Garp’s father, the brain-damaged ball-turret gunner, and which becomes the uniform of an army of feminists, some of whom practice self-mutilation.

“Until I Find You” is not so zany. Although Mr. Irving presents it as a magical trait, Jack’s prettiness is definitely of this world. Mr. Irving’s other big books, “Garp” and “Owen Meany,” came closer to the nuclear-age abandon of Kurt Vonnegut. “Until I Find You” is in the realistic register of Mr. Irving’s “The Cider House Rules.”

Yet there is still something heavy handed in Mr. Irving’s intense treatment of the human body. As a preschooler, Jack regularly resorts to holding his mother’s hand, so much so that his flesh becomes a palimpsest for Mr. Irving’s plot lines: “His hand, the one the clerk had hurt, instinctively found hers. When Jack Burns needed to hold his mother’s hand, his fingers could see in the dark.”

In this fictional world, abuse creates somatic intelligence, which in turn creates personality. That Mr. Irving has now openly discussed his own experience of abuse mitigates the offense readers might take from his relentless reification of freakish handicaps and traumas. But it does not moot the complaint, which, in conjunction with a strictly formal evaluation of Mr. Irving’s oeuvre, shows this book’s shortcomings.

The first fact of Mr. Irving’s prose has always been its confidence. He forms his books like biographies, beginning with birth and ending, if not with death, with latter-life resolution. He introduces minor characters with full biographies, so that the narrative zooms to the end of each character’s life, then shuttles back to rejoin Garp or Jack. The resultant prose has the cross-referenced strength of historical writing.

In “Garp,” the two major characters also wrote their version of events.

That was the beginning, of course, of the book that many years later would make Jenny Fields famous. However crudely put, her autobiography was said to bridge the usual gap between literary merit and popularity, although Garp claimed that his mother’s work had “the same literary merit as the Sears, Roebuck catalog.”

Here the omniscient narrator, moving forward in time, taps Garp, who functions as reflective Greek chorus. Meanwhile, Jenny’s highly opinionated autobiography is always available as a backward-looking political commentary. The book becomes a never-ending back story, an ongoing prequel to itself. The satisfaction of narrative revelation under such conditions is unusual and sharp. “Until I Find You” is regrettably simpler. It does contain great echoes and exciting Doppler effects, and the elder Jack occasionally intervenes, parenthetically, in the narration of his childhood: “To his shame, he basically liked Mrs. Machado. (He would recognize only later that this was part of the problem.)”This kind of narrative doubling is strictly interpretive; it extends understanding without complicating it.

“Until I Find You,” though overwhelming in its completeness, lacks the game weirdness of Mr. Irving’s earlier and greater achievements.