Some movies tie everything up neatly with a bow at the end. The princess marries the prince and they live happily ever after, the killer is found and arrested, that kind of thing.
But with other movies, the bow is dirty, or loose, or sometimes missing altogether. Their endings are more ambiguous or open-ended or at least require a bit of thought afterwards. And some have inspired fan theories that range from the plausible to the, um, inventive.
This discussion will include some spoilers so proceed with caution.
Some time ago I was discussing The Third Man with a colleague. He came up with the theory that, at the end, the ruthless black marketeer Harry Lime (played by Orson Welles) is not nodding at his old friend Holly (Joseph Cotten) to kill him, but is triggering a previously discussed plan to spirit him away. I scoffed at this and began stating obvious objections - such as, would the nearby policeman who's been in pursuit of Lime the whole time let the criminal get away a second time when there's no indication the cop is corrupt? - but he wouldn't hear of it.
It seemed ludicrous, but there are plenty of films where endings or other important points are (usually deliberately) left open for the audience to legitimately interpret or fill in with their imaginations. The internet was made for coming up with and debating such ideas.
An early example of an open ending is The Birds. Alfred Hitchcock's horror film ends with the main characters getting into a car and driving off, surrounded by flocks of birds that are, at least temporarily, not on the attack. There's not even the comfort of the then-common ''The End" card as the image fades to black. It's unsettling and prone to multiple interpretations, but so is the whole movie. Why do the birds start attacking? Does this represent the revenge of nature against man? Does the arrival of Melanie (Tippi Hedren) provoke the attacks? Screenwriter Evan Hunter scoffed at the search for deeper meanings, saying, "We were trying to scare the hell out of people. Period." But that hasn't stopped the debate.
One of the best known examples of ambiguity comes from the science fiction film Blade Runner, even if those involved don't agree with each other: is the main character, Rick Deckard, a man who hunts down and kills replicants, a human or a replicant himself?
Harrison Ford, who played Deckard, thought the character was human but director Ridley Scott thought he was a replicant. Screenwriter Hampton Fancher said Deckard wasn't a replicant but that he had been in one draft. The in-film likelihood shifts depending on which version you watch: the original is the most open but in another cut Deckard's eyes glow in one shot in replicant fashion and he dreams of a unicorn. Later, his colleague Gaff leaves an origami unicorn in Deckard's apartment, which seems to be either one heck of a coincidence or an indication Gaff knows Deckard really is a replicant (how else would he know about the unicorn?).
But then there's the sequel, set years later, in 2049: Deckard is still alive despite the replicants supposedly having only a four-year lifespan - apart from Rachel, with whom Deckard developed a relationship in the first film. Could Deckard be human after all? Or is he another replicant with longer life who ages? I lean towards the "replicant" idea myself, but not 100 per cent, and there's plenty on this to look at online if you're so inclined.
The Shining has a head-scratcher of an ending concerning the exact fates of the main character. Had hotel caretaker Jack in The Shining been there longer than we thought? Given the supernatural nature of the film, such ambiguity works. The Shining has inspired multiple theories and even a documentary, Room 237, exploring them.
Mulholland Dr. (or Drive) is one movie where the whole thing is pretty mysterious - it's a Hollywood story, yes, and an unsettling one, but piecing it all together is a challenge. Maybe there is no ultimate solution (if there is, David Lynch isn't telling, though he did provide "10 clues" towards unlocking it). Is it real life? It it just fantasy? Maybe both?
Birdman's ending, with the main character's daughter looking up and out the window is another case where you have to come to your own conclusion.
And at the end of Shutter Island, is Leonardo DiCaprio's character fully or temporarily compos mentis, or neither, as he goes to meet his fate? I'd say one of the first two, given the evidence provided: it's a deliberate decision.
For a mystery within a movie, there's the suitcase in Pulp Fiction that hitmen Vincent (John Travolta) and Jules (Samuel L. Jackson) retrieve. When it's opened - the combination is 666, hmmm - there's a glow from within but we never see the contents or hear what they are, just that whatever is in there is "so beautiful". One theory is that it contains the soul of the hitmen's boss Marsellus (Ving Rhames), which was taken out via the back of his head (hence the bandage) and which Vincent and Jules have been sent to retrieve.
Director and co-writer Quentin Tarantino said the contents were whatever the viewer wanted them to be. Co-writer Roger Avary thought the light bulb orange was a mistake as it implied the contents had to be supernatural.
Then there's the old question of "Who killed the chauffeur?" in The Big Sleep (1946). The story goes that the screenwriters asked the director, Howard Hawks, who asked the book's author, Raymond Chandler, who said he didn't know either. It's an unanswered question in both the book and the movie but not a major concern.
And maybe that's the point. Sometimes a movie is just a movie.