Psycho has one of the weirder follow-ups in movie history, director Gus Van Sant's near shot-for-shot remake from 1998. Almost the exact same script, mostly the same camera angles (with exceptions both for artistic reasons and for moments when the crew simply couldn't replicate how the 1960 film was done), Bernard Herrmann's music redone to be The Same But Fuller and Louder; and with different actors and production designers, who added their own creative decisions to the thousands that make up a movie. The result is, I have thought since it came out, fascinatingly odd; it doesn't quite work, but the ways in which it doesn't work — and, at times, almost works — make me think about the film more than you'd expect. (To brag on myself, I'm especially proud of that review.)
The very nature of what Van Sant did — remake the movie almost exactly — led to people asking Really? Which led to the rumor What if he's doing something different? What if it's the same movie...until the shower scene?
And while that almost certainly never would have happened, I wonder what such a film could have been like. Gus Van Sant is a perverse enough filmmaker that I wouldn't have put it past him...but, how to change it? The book's story and the film's are almost identical; there aren't different story threads to mine from what Bloch wrote.
First possible divergence: Marion Crane doesn't die.
She fights back enough to surprise "Mother," or (perhaps more likely) "Mother" doesn't want Marion to die — "Mother" and Norman's motivations could conflict enough that "Mother" pulls up short, wounding Marion but not killing her. Thing is, this would almost certainly blow the story's big twist: how would the film then hide that "Mother" and Norman are the same? But since that's such a known Big Twist, maybe blowing it so soon could have worked. Watch it be revealed by Norman and "Mother" "arguing" "with" "each other" — really Norman in the wig and the dress changing voices — and Marion realizing how deep in trouble she's in because of Norman Bates.
Plus you have the dynamic of Norman so conflicted about sex, and here's Marion attractive and naked and (though he might not care and "Mother" wouldn't care) terrified of what he'll do. What if, due to his hangups, he couldn't do any more? And what would happen when Marion realized that? This is going in Misery directions, in my mind. What could Marion — wounded, but with her faculties intact — do? What would she do?
Weirdly, this could happen and the rest of the story — Marion's sister Lila getting concerned enough to seek the help of police and Marion's boyfriend Sam, P.I. Arbogast getting on the case — could keep playing out exactly the way it does in the book or the first film, and that would make for a fascinating push-pull. Changed scene, same scene, changed scene, same scene, until the storylines connect. And maybe Sam, Lila, the sheriff, and/or Arbogast showing up could massively complicate the confrontation between Marion and Norman/"Mother." THEN who knows how it would end.
Second possible divergence: Norman flees.
Unlikely. Norman's sense of duty is too strong. Having killed Marion Crane, he had to Do Something About It, and clean away the evidence then try to protect "Mother" from discovery. But if Crane's murder were the last straw for him, maybe he could/would flee, getting into either his car or Marion's, worried that someone else may show up at the hotel and stumble onto "Mother" but relieved that she could not hurt any people elsewhere. And the more I think of this, the more I kind of like the idea...because Norman'd be completely wrong, and putting others in danger by fleeing.
This has a different problem from the first idea: it'd then be harder to reveal who "Mother" really is. It could be confusing — overly confusing — to audiences the first time. Also, he'd be more likely to run into characters we haven't met before, which diffuses the stakes. And having him run into characters we have met could be too contrived.
Divergence 2.5: Norman flees, but can't bring himself to run far. He holds himself up, then maybe returns to the hotel...as someone else we've met also arrives...
Maybe. Maybe. But I'm not excited by the idea. At best, in the context of Vince Vaughn's more tic-heavy performance as Norman in Van Sant's film, this conflict might be easier to show than it would have in the 1960 film with Anthony Perkins' more contained, quiet, and still performance.
Third possible divergence: Marion's trail goes cold.
Something happens to make Marion's boss not want to find Marion and the money she stole (maybe the Monday after Marion fled, cops arrest the boss for reasons having nothing to do with Marion's crime). Or circumstances could make it seem like Marion would be out of contact for non-dangerous reasons, and neither Lila nor Sam get worried enough about where she is. "She's probably fine," they think, while Norman Bates makes Marion and her things disappear.
This is a depressing idea. And probably far too out-of-nowhere a plot twist. At best, it might allow for more time to show Norman and "Mother's" conflict, but this way, the story might simply fizzle out.
Fourth possible divergence: That Cop shows up. Again.
...no, in context there would've been too much chance for that to seem silly. Hell, for me it was a Point of Contention in the original film: the cop follows Marion past a point I'd expect him to follow her, almost to the point of plot contrivance. (The theory is that That Cop, a character added for the film, is mainly there due to Hitchcock's well-known dislike and distrust of cops.)
This has been an intriguing exercise in "What if?" I've kind of been imagining a Psycho Alternate Universe, using the elements Bloch, Hitchcock, Stefano and others came up with and remixing them. And I'm still impressed with how strong the original story is.