John Irving's 15th novel, "The Last Chairlift," is hard to miss: At more than 900 pages, it rivals the length of "David Copperfield" and "Moby-Dick," two epics he admiringly references throughout the book.

But the new novel's true touchstone is Irving's own fiction. Indeed, the contents of "Chairlift" may be so familiar — a fatherless son, a headstrong mom, wrestling, the writing life, a mute woman, a transsexual friend — that at times it feels like a reboot of his 1978 classic, "The World According to Garp."

But the world has changed since 1978, and Irving has made a few tweaks to the narrative. First, as the book's bulk suggests, is its scope. Ranging from the end of World War II to the Trump era, the novel follows the life, family and romantic failures of its novelist hero, Adam. He aches to learn the identity of his father. But his mother, a ski instructor at a Vermont resort, isn't telling.

"The issues we have," a cousin tells Adam, "are all about sex." True: "Chairlift" is largely about sexual connection, which is sometimes played for laughs, especially around Adam's awkward early experiences. ("You never screw someone in a cast, sweetie — you just don't!" he's told after a bedroom injury.) Sometimes it involves more conventional matters of infidelity.

But Irving is also seriously targeting six or so decades' worth of sexual suppression and demonization. The story's key moments involve homo- and transphobia, the Reagan administration's willful neglect of the AIDS crisis, and religious hypocrisy. In every era, being outspoken against those forces makes characters a target. A fair amount of blood is shed across the novel's pages.

Within that broad theme, Irving weaves in a few additional ones. Ghosts are a constant presence around Adam, both in Vermont and at an Aspen hotel that plays a central role in the story, symbols of family tragedy and neglected history. Death, too, is always lurking, as Adam mulls his responsibility to himself and others before he loses them. A line from "Moby-Dick" keeps him centered and somewhat optimistic: "Death is only a launching into the region of the strange Untried."

But if "Chairlift" centers on the big stuff — love, sex, death — it also feels oddly small. Irving tries a couple of rhetorical gambits throughout the novel, most notably two extended sections in screenplay format. Still, Adam's essential quest is straightforward, and the novel's bulk only thins out its urgency. A book half or even a third of its size could have done the job more powerfully.

There are moments, though, when Irving's old magic emerges: his wit and fearlessness around sex, and his grasp of the wide ripple effects of intolerance. "There's more than one way to love people, Kid," young Adam is told early on. If Irving keeps hammering that point, over and over again, it's because he's collected years of evidence that some people never hear it.

Mark Athitakis is a book critic and author of "The New Midwest."

The Last Chairlift

By: John Irving.

Publisher: Simon & Schuster, 912 pages, $35.

Event: PenPals, 7:30 p.m. March 23, 2023, and 11 a.m. March 24, 2023, Hopkins Center for the Arts, tickets $35-$55.