This week HitFix is revisiting some of the key turning points in recent entertainment history and considering what would have happened if history had turned a bit differently. What if...?

In the long and luridly storied history of Hollywood breakups, you'd be hard pressed to find an uglier one than the nuclear meltdown that occurred between Woody Allen and his longest-serving muse, Mia Farrow, in 1992. The quintessential New York writer-director and the Beverly Hills-born actress -- an industry princess who had already been married to Frank Sinatra and Andre Previn -- were an unlikely match when they got together in 1980, but their relationship proved a fruitful one, producing three children and 13 films together. Allen's a director known for reusing favorite actors, but not even former partner Diane Keaton approaches Farrow for the title of his most frequent collaborator: between such films as "Zelig," "The Purple Rose of Cairo," "Hannah and Her Sisters," "Crimes and Misdemeanors," "Alice" and their brilliant parting effort "Husbands and Wives" -- a film released in the heat of their breakup, and a brutally close-to-the-bone blueprint thereof. 

If you don't know what happened then, it's safe to assume you weren't of headline-reading age 21 years ago. Here's the short version: Allen had an affair with Farrow's 20-year-old daughter Soon-Yi, and in the bitter separation and custody battle that ensued, Farrow alleged that Allen had sexually molested their seven-year-old daughter Dylan. The charges were dismissed, but the scandal lingered long after Farrow handily won the court battle and Allen quietly married Soon-Yi.

Yet while it was Allen whose personal reputation took the biggest knock from the whole messy occurrence, it was Farrow whose film career receded once their collaboration was over. Allen continued his film-a-year routine without a hitch, with Hollywood's great and good still flocking to be cast in films and the Academy nominating him for such follow-up efforts as "Bullets Over Broadway" and "Mighty Aphrodite." Farrow made a trio of features in the mid-1990s, before giving herself over largely to TV and -- far more significantly -- her extensive charity work. Hardly surprising, given Hollywood's usual treatment of middle-aged actresses. But what if -- hard as it may be to imagine now -- things in the Allen-Farrow household hadn't gone so vertiginously south, and their collaboration had continued? 

What if Woody Allen and Mia Farrow had stayed together?

Three things that might not have happened:

1. The Woody Allen-Diane Keaton reunion. This, we know, definitely wouldn't have happened. Allen wrote "Manhattan Murder Mystery," his fizzy 1993 Hitchcock homage, with Farrow -- as usual -- in mind for the female lead, the neurotic wife-turned-amateur-sleuth of Allen's even more neurotic New York literary editor. That, of course, was before their relationship collapsed, so when the time came to make the film in the immediate aftermath of the breakup, Allen called in a favor from his former muse Diane Keaton. Their first film together (bar her fleeting cameo in "Radio Days") since "Manhattan" 14 years previously, it was a fun nostalgia trip that earned Keaton a Golden Globe nod, though Allen admitted he'd have written the film differently for Keaton: "[Mia's] not as broad a comedian as Diane is... Diane made this part funnier than I wrote it." Might the Farrow-starring "Manhattan Murder Mystery" have been a more dramatic affair? In any event, the Woody-Diane reunion proved to be a one-night-only deal. She's not doing much these days -- how about it, guys? 

2. Woody's Eurotrip. Given that Allen didn't make a single film without Farrow in the 12 years they were an item, it seems reasonable to project that she would have remained a fixture in his ensembles as long as they'd remained together. That opens pretty much a limitless realm of "what if" questions regarding Allen's subsequent filmography. It's easy enough to see where Farrow would've slotted into, say, "Mighty Aphrodite" (sorry, Helena Bonham Carter); "Sweet and Lowdown," not so much. But it's his European phase of the new century -- his diversions into London, Barcelona and Paris -- that is hardest to imagine with Farrow on board: the liberated production focus and youthful focus of those films feel very much the result of a set-in-his-ways auteur consciously making a fresh start. Could he have made them with a partner of over 25 years' standing? An older-skewing "Midnight in Paris" could conceivably have been made with Allen and Farrow in for Owen Wilson and, perhaps, Rachel McAdams -- but would "Vicky Cristina Barcelona" have been written at all? 

3. Farrow suffers the curse of "The Omen." Working with Allen, along with raising their rambling family, was pretty much a full-time job for Farrow: in the time they were together, the only non-Allen feature she appeared in (voice work in "The Last Unicorn" excepted) was 1984's "Supergirl." Having only been served her partner's scripts for over a decade might have dulled her project-choosing abilities a bit -- not that Hollywood producers were likely giving the actress much choice as she headed into her fifties. A continued routine of annual Woody joints may well have removed Farrow from such projects (for better or worse) as Zac Braff's "The Ex," the "Arthur" animated franchise and sundry second-rate TV movies -- but she'd surely have been spared the indignity of chewing the scenery in 2006's limp remake "The Omen." She was the best thing in it, but still: better off out of it. 

Three things that might have happened:

1. Farrow does a whole lot more feature films... and perhaps gets that elusive Oscar nomination. With the exception, of course, of Roman Polanski, no filmmaker had a better idea than Allen of what to do with Farrow's fragile screen presence -- whether playing up to it in melancholy character studies like "The Purple Rose of Cairo" and "Another Woman," or casting her brashly and sucessfully against type in "Broadway Danny Rose." It'd have been interesting to see what roles he'd have written for her had they grown older together -- Farrow wrote in her autobiography that she felt disengaged from her ensemble roles in the later, sourer years of their relationship, but might a happier outcome have yielded more devoted valentines in the "Alice" or "Purple Rose" vein? And if so -- with her Allen collaborations having yielded multiple BAFTA and Golden Globe nods for the actress, as well as a National Board of Review win -- the Academy would have had to relent sometime, right?

2. Woody produces more dramatic fare. Allen's aforementioned comment Farrow's subtler comic style is a telling one: the early years of their relationship produced fleeter comic exercises like "Broadway Danny Rose" and "A Midsummer Night's Sex Comedy," but as the 1980s wore on, he seemed increasingly attuned to the inner dramatist that had previously written "Interiors" -- whether fused with comedy in films like "Crimes and Misdemeanors" and "Hannah and Her Sisters," or given to outright Bergmania in "Another Woman" and "September." It's speculative, of course, to say that the sensitive, serious-minded Farrow inspired this phase of his career, but it's worth noting that their breakup was immediately followed by a return to lighter comedies like "Bullets Over Broadway" and "Everyone Says I Love You." Would this tonal break have occurred had his personal life stayed on course? Perhaps, but we also might have waited a little less long for his return to dramatic writing in 2005's "Match Point" and this year's "Blue Jasmine" -- a film it's easy to imagine him writing for Farrow 20 years ago.

3. Woody gets Twitter. Okay, this is a silly one. But Farrow has proved surprisingly active on Twitter, using her feed both to abet her humanitarian work and to show off an unexpected streak of droll humor -- her dry, casual tweet a couple of weeks ago about watching "Sharknado" with Philip Roth fooled a lot of people and spawned a short-lived Twitter meme. If she's embraced it, could she have talked Woody into doing the same? Probably not. One senses he'd regard social media much as he does cars, Los Angeles or the Oscars -- with a mixture of disdain and terror. Still, a regular feed of mordant Woody one-liners would be a must-follow. And even if he couldn't be persuaded, there's the hope that Farrow would share some choice domestic tidbits.

Did history work out for the best?

Well, yes and no. One is loath to say that any breakup that hurts as many associated parties as this one -- and in such a public manner -- is "for the best," though both seem to have effectively moved on: Allen's marriage to Farrow's now-estranged daughter is still going strong, while Farrow has further filled her life with children and humanitarian work. But we're not passing a verdict on anyone's personal life: are their careers better for the way things turned out? Certainly not in Farrow's case, though perhaps she'd simply have lost her taste for screen acting anyway. Allen's filmography may have followed an uneven trajectory in the last 20 years, but it had never been blemish-free: I'd argue that his Farrow period was the richest and most adventurous of his career, but it still produced the occasional misfire. With "Midnight in Paris" having brought him a fourth Oscar last year, and "Blue Jasmine" currently earning him rave reviews, history has worked out pretty well for him -- though I'd say cinema is a little poorer for having fewer Allen-Farrow collaborations than it could have done.

Do you think film history was affected by Woody and Mia's breakup? And if so, for better or for worse? Share your thoughts in the comments.