George P. Cosmatos' terrific horror/thriller Of Unknown Origin is occasionally referred to as "Jaws but with a rat", so I guess it's fitting that, like Spielberg's masterpiece, the film is based on a book. Chauncey G. Parker's The Visitor was published in 1981, and according to the film's screenwriter Brian Taggert, it was somewhat based on a true story - like his protagonist Bart Hughes, Parker was a banker who renovated a New York brownstone and saw his work threatened by a rat he couldn't seem to kill. It's a shame Parker wasn't around to tell this story himself on Scream Factory's special edition Blu-ray (he passed away in 2013), which is on shelves today - but I hope he knew before he died that the film derived from his experience, largely ignored when it was released in 1983, had become quite a favorite among horror fans.
It's certainly one of mine; I've written about it a couple of times since seeing it for the first time* in 2009 and frequently recommend it to people who are looking for something they haven't seen yet. I picked up Parker's novel (albeit a "Movie Tie-in" reprint with the new title) a couple years ago but only got around to reading it now, curious as to what the differences were, if any. Turns out they're pretty similar, and even kind of complement each other in certain ways, which is unusual for a film adaptation. In the film, Bart mentions having traps from a previous issue with mice, and in the book we get more of that story and why their reappearance would trouble him so, and on the other hand, seeing the rat (which Parker doesn't spend much time describing) gives Bart's unfilmed struggles with it more exciting/less laughable, as we know not to picture your standard New York-sized rodent giving him so much trouble. Ninety-nine times out of a hundred, the book is superior to the film, but in this case I think they're pretty equal in terms of quality; some of the film's changes were for the better, others I wish Taggert had stuck with what Parker came up with originally. It's a brisk read (I would hesitate to call it a "beach novel" myself, but I wouldn't argue with it either) and well worth tracking down for those who liked the film and/or enjoy reading.
For you lazy types, I'm gonna explain what's different!
The biggest change until the ending is that Bart's family is gone when the book begins, so we never really meet them beyond his wife's voice on the phone. They're also reduced in the movie; Parker gave Bart two daughters and a son named Bart Jr, but in the movie there's just the one son, now named Peter (possibly a slight in-joke if you think about it), a change that makes no real difference in the long run, though Taggert retained the remnants of having a larger family by keeping the big basement playroom (complete with dollhouse and several board games), which seems unnecessary for an only child who has his own bedroom in a three story house. The novel isn't told from a first person perspective, but it might as well be - we're with Bart and pretty much only Bart throughout, never seeing things from anyone else's perspective. That said, Taggert excised a number of the supporting characters, such as a pair of well meaning diner employees who get on Bart's nerves by querying him about why the rat fight is taking him so long, and a company doctor who Bart is ordered to see when his work starts getting sloppy.
That ties into one of the film's other big adjustments: Bart's work life. Bart and his job are the same, but I feel we see more of his office and his coworkers (especially his secretary, played by Jennifer Dale) in the film than we do in the novel. In fact, the big dinner party that Bart derails is a complete invention of Taggert's screenplay - there is no such dinner in the novel, and Bart's trip to the library is largely useless in Parker's version of events. If the movie makes any blunders, it's that it dives into specifics about Bart's job duties early on, before we're sure what kind of movie it is, which might turn some viewers off as there are few things less interesting than bank talk (and unlike Adam McKay, Cosmatos didn't think to put Margot Robbie in a hot tub to explain what they're yammering about). I get the point of these scenes: we need to see what Bart's world is usually like, and quickly, to see how much it becomes unraveled by the rat's presence in his home, but in the book Parker is able to get that done through interior monologue and quick summaries of the daily office events, not full scenes. The film has to settle for brown-nosing coworkers babbling about the equivalent of "TPS reports" before we've gotten any rat action - it's not a crippling flaw, but one that Taggert didn't quite crack when adapting Parker's novel for a visual medium.
Taggert also removed a separate plumber character and gave his lines/reason for existing to Cletus, the local handyman who assists Bart a few times in both versions of the story. He's also the one who first suspects a rat may be the problem in the movie, unlike the book where Bart sees a news special (from Geraldo!) on TV about a rat attack and starts getting it in his head on his own. It's one of the many instances in the book where you almost wonder if everything is in Bart's imagination; apart from the plumber early on, no one else enters the house, and whenever someone asks him why he looks like shit, prompting him to run down his recent battles with the rat, he DOES sound crazy when everything is summarized, especially after he kills its litter (on purpose here; in the movie it comes off as more of an accident) and becomes convinced the rat is out for revenge. He drinks heavily as well in the book (whereas the movie just has him occasionally imbibing like anyone would), further deteriorating his ability to function and getting him even closer to getting fired from his job. Had I not already seen the movie I probably would have been leaning toward there being no actual rat (or at least, not one that he was still battling three weeks later), and it's not until the novel's closing page (not counting an epilogue I'll get back to) that anyone else sees the damn thing, when it's finally dead.
A psychological approach might have still made for a good movie, but the filmmakers knew they'd need more to put in the trailer, so there are a few nightmare scenes in which the family is being terrorized (in reality, they never once encounter it), whereas in the book Bart just dreams about more rat attacks against him. The movie also adds the only casualty to the story: a poor stray cat that Bart brings in to fight the thing, only for it to lose. But the movie is also funnier; in the novel we're basically inside the head of a man who is going insane, which isn't particularly amusing, but on film - with a gifted actor like Peter Weller bringing the character to life - there is license to add some levity to the situation. His bemused reaction to the rat cutting the power, telling the rat that the town isn't big enough for them both, and using a copy of Moby Dick to bang on the ceiling are all inventions of the film (I don't want to keep attributing everything to Taggert; I'm sure Cosmatos, Weller, and producer Pierre David all had their input). Also, unless I missed it, the book version of Bart is never smart enough to install a hammock in his bedroom, if any mega fan of the book went to see the movie, they got to be just as surprised as anyone when Bart retreats from a battle and dives into his new sanctuary, which hadn't been previously established (if it was, it wouldn't be as funny a moment). That said, there isn't much change to Bart as a character; both versions are very neat and orderly and focused on the details - i.e. the worst kind of person to have to deal with something unpredictable like an angry rat. It's easy to see the novel version, who loves going to hardware stores and admiring the neatly shelved rows of tools, being the same guy from the movie who adjusts an imperceptibly askew painting and plucks at a stray thread from his secretary's blouse.
The climax also has a few key changes. For starters, Bart doesn't destroy the rest of the house during the final battle in the book - they pretty much stick to the cellar, and he doesn't knock out some pipes in the process, giving it a much more low-key vibe. In fact, finally killing the rat is something of a bonus in the book, as he has surrendered and is actually in the cellar to clean it up before a realtor shows the place to a client who wanted to buy it. He has a poker to defend himself just in case, but isn't really planning for battle when the rat goes on the offensive, allowing him one last chance to kill the damn thing before the realtor arrives. As it turns out, the "new buyer" is actually his boss and the company doctor, who have apparently decided that Bart needs to be committed and are coming to help take him away, so it's pretty good timing that the rat a) showed up again and b) got killed, as the men enter expecting to find a crazy man and instead find him bloodied and injured, with a giant rat in a pool of blood next to him. Parker doesn't bother explaining if this gets him back on track at his job, however; the movie more or less suggests that his boss recognizes he needs to work some shit out and gives him the time to do so without ever resorting to the drastic measures that his novel counterpart was prepared to do.
Then again, Parker's Bart isn't too worried about his future, as in an epilogue we find out that they do end up selling the place and moving into a luxury apartment, only for his wife - making her first physical appearance in the book - to discover some rat droppings in the kitchen. Is it the never-seen father rat, out for revenge? A coincidence? Did he not really kill his nemesis after all? It's a typically lame horror movie ending, basically, suggesting a sequel that likely will never come, so I find it kind of funny that the actual horror movie version omits it in favor of an all timer one-liner (when Mrs. Hughes sees the damaged to their home and asks what happened, Bart shrugs "I had a party.") that sends us on our way in a cheery mood. Of course, the movie's failure at the box office ensured there would be no sequel anyway, so I guess it was a doubly good decision on the filmmakers' part not to suggest there would be any further adventures.
Alas, there wouldn't be much more from Parker as an author, either. He released one other book in 2001 called In Sheep's Clothing, but no listing for it I came across even explains what genre it is, let alone what it's about or if it's any good. It's a shame he wasn't more prolific; his first attempt (well, first published one anyway) was a fine read and became an equally good movie with a modicum of alterations, suggesting a flair for simple stories well told and engaging characters that good actors would happily sink their teeth into. I would have loved to have seen more from him, but then again perhaps it was his personal experience that helped make the book/movie so memorable, so I guess for his sake it's for the best there were no proper followups. Gives him a 100% track record though, so eat it, King/Koontz/etc!
*First time in its entirety, that is; I caught the ending on cable as a kid and it haunted me for years trying to figure out what "that movie with the rat and the guy in the water" was.