Toward the end of “The Rum Diary,” the film based on the Hunter S. Thompson novel, there’s a scene that appears to come straight from the author’s vintage work.

Two journalists are sitting around a derelict San Juan, Puerto Rico, apartment, having just ingested an unknown hallucinogen. Nothing happens until one of them ― a Thompson stand-in named Paul Kemp, played by Johnny Depp ― sees the other’s tongue start to grow out of his mouth like some tubular pink snake.

Depp humps and haws, his mannerisms not unlike those he used when playing Thompson in “Fear and Loathing in Las Vegas,” a portrayal modeled closely on Thompson himself. Call it Fear and Loathing in Puerto Rico, I suppose.

All of which is well and good, except for this: “The Rum Diary” (Simon&Schuster: 204 pp., $15 paper) is not vintage Thompson; rather, it is pre-vintage, an example of the author’s work in utero, the earliest of his writings to appear in print.

Composed in the early 1960s, it was lost, or set aside, after he couldn’t get it published, only to be rediscovered in 1998.

By then, Thompson was all about recycling ― beginning with “Songs of the Doomed” (1990), his books take on the catch-as-catch-can aspect of scrapbooks, full of outtakes and B-sides with occasional bursts of brilliance, refracted through the filter of his myth. One might even trace the impulse back another decade, to 1979’s “The Great Shark Hunt,” but I’ve always been partial to that collection, which gathers his original 1965 Hell’s Angels piece for the Nation (Carey McWilliams was his assigning editor) as well as such gonzo landmarks as “The Kentucky Derby Is Decadent and Depraved” and “Strange Rumblings in Aztlan,” which details the 1970 killing by a Los Angeles County sheriff’s deputy of Times columnist Ruben Salazar.

“Strange Rumblings in Aztlan” appears, again, in “Fear and Loathing at Rolling Stone: The Essential Writing of Hunter S. Thompson” (Simon&Schuster: 572 pp., $32.50), a new collection, edited by Thompson’s friend and sometime nemesis Jann Wenner, that also includes parts of “Fear and Loathing in Las Vegas” and “Fear and Loathing: On the Campaign Trail ‘72.”

The book aspires to present an overview of Thompson’s work for Rolling Stone, but although it features his two most enduring later pieces ― “A Dog Took My Place,” a scathing 1983 dissection of the Roxanne Pulitzer divorce trial, and “Fear and Loathing in Elko,” a 1992 fantasia about Clarence Thomas ― it mostly serves, like the film adaptation of “The Rum Diary,” to reinforce the not-so-secret-message that Thompson, who shot himself to death in February 2005 at age 67, was ultimately a victim of his image, a writer who, despite having once been among our most vital cultural observers, produced little worth reading in the last quarter century of his life.

This is why the book “The Rum Diary” is so interesting, because it offers a counterpoint, a glimpse of Thompson as he was forming, before the attitudes that later trapped him became his stock-in-trade.

The novel is strongly autobiographical ― like Kemp, Thompson was a reporter at an English-language paper in San Juan in 1960 ― but even more, it’s marked by a nascent world-weariness, a sense of Puerto Rico as a last way station for has-beens and never-weres in retreat from responsibility, which gives it an air of freedom and foreboding all at once.

“I was getting a little too old,” Kemp tells us, “to make powerful enemies when I held no cards at all, and I had lost some of my old zeal that had led me, in the past, to do what I damn well felt like doing, with the certain knowledge that I could always flee the consequences. I was tired of fleeing, and tired of having no cards.”

On the one hand, that’s classic Thompson, blending gamesmanship and clarity. On the other, it’s unexpectedly reflective, especially from an author for whom consequence was often just another dirty word. The tension only makes “The Rum Diary” more revealing, with every proto-gonzo riff ― “I was beginning to get the fear,” Thompson writes. “‘You better carry a gun,’ Moberg advised me. ‘They’ll be after you now. I know those swine ― they’ll try to kill you.’” ― offsetting more contemplative passages, as when he notes a character’s dissolution, or details Kemp’s detachment at trading his ideals for a high-priced copywriting gig.

“I sat there a long time,” Thompson notes, “and thought about a lot of things. Foremost among them was the suspicion that my strange and ungovernable instincts might do me in before I had a chance to get rich. No matter how much I wanted all those things that I needed money to buy, there was some devilish current pushing me off in another direction ― toward anarchy and poverty and craziness.” Such moments open a window on the real Thompson, who more than anything seems caught between his extremes and the desire for something more.

Given how Thompson ended up, this feels a bit like a lost promise ― a sentiment that, inadvertently or otherwise, “The Rum Diary” movie also provokes. It’s not an unfaithful adaptation, just one that sustains, or even relies on, our preconceptions, as “Fear and Loathing at Rolling Stone” does.

For Thompson, the window between creation and calcification was so narrow, less than 20 years from “The Rum Diary” to “The Great Shark Hunt.”

Then, he fell prey to the image he’d created, becoming invisible as anything but caricature. That the caricature is now how we remember him is only one of the ironies here. “We’re over the hump,” Kemp declares at the end of the novel. “The ride gets pretty ugly from here on in.”

By David L. Ulin

(Los Angeles Times)