"The Rum Diary" is not a very good book.

It's an early piece of work by Hunter S. Thompson, but anyone who picked it up looking for the voice that distinguished his classic work was likely disappointed.  He wrote it in his early 20s, and it went unpublished until 1998.  More than anything, it serves as a fascinating glimpse at a raw, unpolished talent, and it offers up some autobiographical details hidden amidst the twists and turns in the story of Paul Kemp, a reporter who moves from New York to San Juan, Puerto Rico in order to kick off his career as a writer.

As a film, "The Rum Diary" is far more interesting, due in no small part to the collision of talent that it represents.  First, there's Johnny Depp, whose performance as Thompson in Terry Gilliam's "Fear and Loathing In Las Vegas" is positively inspired, a spooky case of near-possession where an actor absolutely channels a real-life figure.  The idea of seeing him play Thompson, or a Thompson stand-in, at an earlier point on his slow slide into self-medicated madness is undeniably appealing.  Then there's writer/director Bruce Robinson, whose "Withnail & I" is one of the greatest films of the '80s, and one of my very favorite British films of all time.  He hasn't made a movie since "Jennifer 8," a Hollywood misfire that killed his career dead, and from the moment he was announced as the man behind the camera, this became one of those films I almost refused to believe really existed.  The idea of Depp reaching out to Robinson, who was always Hunter's first choice to make a "Fear & Loathing" film, and somehow coaxing him out of retirement would be interesting enough even if it were just a straight adaptation of the book.

It's not, though.  It's something far stranger and richer than that, and while I don't think it's a totally successful film, it is wholly interesting.  In some ways, you could argue it's a thinly veiled remake of "WIthnail" with some bare bones detail from Thompson's book grafted onto the top of it.  There are many structural similarities and even some direct character corellations.  In other ways, this is sort of like what Cronenberg did with "Naked Lunch," where his film is more of a "how the novel was written" than an attempt to actually film the novel.  The Paul Kemp in the film is far more Hunter S. Thompson than the Kemp in the book, and you could almost view this like Thompson's superhero origin story.  It's a film about a young writer struggling to find the voice that will define him, and the moment he realizes what his calling is and we see him step up to become that writer, the movie's done.

It's a shaggy film, with a lot of weird left turns, and that's sort of what made me fall in love with Robinson the first time around.  Here, as soon as Kemp arrives in San Juan, he falls in with two reporters who are, to put it kindly, complete degenerates.  Sala (Michael Rispoli) can at least hold it together enough to get through a work day, but Moburg (Giovanni Ribisi) has burnt his cortex out with rum and is barely functional as a human being at this point.  They both seem determined to introduce Kemp to the San Juan they know, a crumbling piss-pot that only exists as a rest stop before they move on to some other job in some other place.  Their editor, played by Richard Jenkins, seems enormously put upon and barely able to hold together his joke of a publication.  Kemp is looking to make a mark, but he has no idea how to do it or even really what to write.

He also meets Sanderson (Aaron Eckhart), a former employee of the paper who has graduated to land development, and right away, he can see that Sanderson chose the good life.  It's obvious in the cars he drives, the clothes he wears, the place where he lives, and in Chenault (Amber Heard), the girl he keeps.  She is pure arm candy, and Sanderson seems to view her the same way he views those expensive cars, as a standard of measurement that demonstrates his success.  Kemp sees her as something else, though, a vision, an obstacle to his happiness.  Once he's seen her, nothing else will do, and that's a dangerous train of thought for a man who has nothing.

Much of the film plays out as a battle for Kemp's soul, what little evidence there is of one.  I find it really interesting to see Depp, who is over a decade older than he was in "Fear and Loathing," successfully playing a much younger version of the same character.  Many of the same mannerisms are there, but turned way down.  This is a young man who still thinks he needs to play the game the same way as everyone else, who hasn't started to indulge his own worst instincts, who hasn't been married yet or divorced yet, who still has hope and optimism built into his world view.  This is proto-Hunter, and Depp does a very able job in showing us how this could easily be the person who will later become the infamous oversized personality known as Raoul Duke.

Special credit must be given to Dariusz Wolski, because for some reason, several cinematographers who have shot films featuring Amber Heard have managed to shoot her wrong.  Here, Wolski makes her glow, and she continues to get better every single time she's in a film.  I think she was cast initially because she's a striking young woman who definitely holds the camera's eye, but I really think it's just been over the last few years that she's started to come into focus as an actor.  It'll be interesting to see how filmmakers handle her and what sort of roles they see her in, because she could easily get sidetracked just by virtue of being stunning.  Here, she and Depp have a really lovely chemistry, and the difference between the way she reacts to Kemp and the way she reacts to Sanderson is all you need to see just how good Heard's gotten.

Ribisi and Rispoli are very good, very funny, and if you squint while they're onscreen, they almost become Ralph Brown's Danny the Dealer from "Withnail" and Benecio Del Toro's Dr. Gonzo.  The difference is that they gradually fall away in importance as Kemp starts to figure himself out.  These guys are the flame that Kemp is drawn to, but he manages to keep from getting burnt at this stage in his life.  It's only later that he'll fly right into it, welcoming the fire.  Here, we have to see that this sort of lifestyle takes a toll on Kemp.  He's not wired to keep up with them.  Not yet.  They are far gone, and he's just warming up.  They are one of the necessary steps on his journey, just like Sanderson.  Eckhart's good here, but it's a fairly standard rich prick role.

Do I wish the film was a more coherent whole?  Yes.  But even in this sort of shambling imperfect state, "The Rum Diary" is an interesting almost, a near miss that leaves you with plenty to contemplate.  It is a noble shot at a novel barely worth reading, much less filming, and the fact that it comes as close as it does to really working is a minor miracle, and one worth seeing.

"The Rum Diary" opens this Friday.