If you're a hardcore Marvel comic book fan - or even a moderately-cored fan of the Marvel movies - you're probably well aware of exactly who Doctor Stephen Strange is.
In fact, you probably think it's a little "strange" that there are still people in this universe (or any universe) with no idea who the character might be. The Doctor Strange movie, starring cerebral fan-favourite Benedict Cumberbatch, is released in just a few weeks, and our appetites have been whetted by several trailers and TV spots.
According to a new Vanity Fair profile, however, just a few years ago Cumberbatch himself had no idea who the character was, responding "Doctor What?" when a journalist suggested he'd be a perfect fit for the role.
In case you're still in a similar state of confusion, here's our need-to-know guide to the world's strangest superhero. (We'll stop using "strange" as an adjective now. We promise.)
1. Who is Doctor Strange? Is he a real doctor?
In the original Marvel Comic books, Doctor Stephen Strange is a talented but arrogant neurosurgeon, who finds himself in a desperate position after a car accident leaves him with damaged hands, unable to perform the complex operations that helped make his name.
Increasingly desperate for a cure, he heads to the Himalayas (the film's trailer names his destination as Nepal) and encounters a mysterious person known as The Ancient One, in the isolated mountain community of Kamar-Taj.
The Ancient One (traditionally shown as an elderly chap with a big beard - more on that later) is initially skeptical about Strange, thanks to the doctor's former obsession with wealth and status.
Luckily, however, she (see next question) senses the potential for good in him, and begins training him to become the new Sorceror Supreme: a semi-mystical being who protects the world from supernatural threats.
2. What about bald Tilda Swinton? Who is she supposed to be?
In a break with traditional casting, actress Tilda Swinton stars in the film as The Ancient One, although according to Marvel president Kevin Feige she is portraying the character's gender in an "ambiguous" way.
"It's funny you ask 'Will Tilda Swinton be playing a woman?' and you ask it because she does an amazing job of being sort of ambiguous in terms of gender," he told IGN. "Clearly she's a woman, but it is very ambiguous in her portrayal."
While some fans are pleased that Marvel has placed an older female actress in a prominent role (Swinton is 55, which really is "ancient" by Hollywood standards) others have complained that the casting is an example of "whitewashing", due to the fact that an Asian character is being portrayed by a white woman.
3. So it's an origin story?
Yes. The official movie synopsis reads:
Marvel's Doctor Strange follows the story of the talented neurosurgeon Doctor Stephen Strange who, after a tragic car accident, must put ego aside and learn the secrets of a hidden world of mysticism and alternate dimensions. Based in New York City's Greenwich Village, Doctor Strange must act as an intermediary between the real world and what lies beyond, utilizing a vast array of metaphysical abilities and artifacts to protect the Marvel cinematic universe.
4. Who is the villain? (And who is the real villain?)
Danish actor Mads Mikkelsen (Le Chiffre in Casino Royale, Hannibal Lecter in NBC's Hannibal) plays the film's main antagonist Kaecilius, a former ally of the Ancient One who later breaks away to follow his own path.
It's been hinted, however, that Kaecilius could be working for (or, indeed, being made to work for) a much darker power.
"What we wanted was a character that was rooted in the real," said the film's director, Scott Derrickson, in an interview with IGN.
"This is certainly what I was pitching from the beginning, was an antagonist who was rooted in the real world... so that there could be an intimate relatability between Strange and his adversary.
"But who was empowered by something else. By something otherworldly. And connected to something else otherworldly, which comes straight from the comics. Another, and I'll say this, another character straight from the comics, you know."
The director then compared Kaecilius to the Lord of the Rings character Saruman (played in Peter Jackson's film by Christopher Lee), a wizard who works for an ancient, more intangible evil named Sauron.
Excited Marvel fans have speculated that Scott's "ancient evil" could be Dormammu, a semi-mystical, demonic being from another dimension, who is one of Strange's main enemies in the comic books.
5. Who else is in it?
Chiwetel Ejiofor plays Karl Mordo, a former pupil of the Ancient One turned villain in the original comic books, whose role has been changed in the film to make him into a more complex, sympathetic character.
"I think that Mordo is the first to recognise the potential in Strange and becomes his primary advocate, initially," said Ejiofor in a recent interview. "Their relationship is complicated. In some ways they're quite similar but that lends itself to tensions between them. But overall he is the tutor that really brings him in."
Rachel McAdams also has a significant role, playing a former colleague of Strange's and one of the film's few grounded, more "human" characters, while Benedict Wong plays Wong, a Masters of Mystic Arts.
Like Mordo, Wong's character has undergone a fair few changes. In the early comic books, the he had a sadly limited role and was sort of Asian sidekick/servant to Strange's hero. But, in the film, he's more of a teacher/comrade in arms.
"Well, I kind of think things like 'manservant' and 'sidekick,' we're just gonna leave back in the past now," Wong told Screen Rant. "I'm very much into looking forward into our modern take and back in on the beginnings of this origin story, now. So, you know, let's turn a whole new page."
"Wong is in our world now, a master at Kamar-Taj training the fellow disciples and sorcerers, a protector of the Sanctum relics and these ancient ritual books, and it's where we'll see Wong and Doctor Strange come together and become, really, allies to fight against these extra-dimensional forces..." he added.
Boardwalk Empire star Michael Stuhlbarg, meanwhile, plays scientist Nicodemus West, Strange's professional rival.
6. How does it fit in with the rest of the Marvel universe?
"The Avengers protect the world from physical dangers. We safe guard it against more mystical threats," explains Wong's Master in the Doctor Strange trailer, in a line that neatly sums up how Doctor Strange is going to slot in to the Marvel Cinematic Universe's "main" storyline.
In other words, the film will be a bit like Guardians of the Galaxy or Ant-Man: a self-contained story, set within the wider Marvel universe, but unafraid to forge its own, perhaps more off-beat path.
Fans have also suggested that the movie could feature the mysterious Time Stone: one of the missing Infinity Stones (a set of super-powerful gems coveted by the series's overall villain Thanos).
The footage below, released by Marvel a few days ago, simply added fuel to this speculation...
,,puᴉɯ ɹnoʎ puɐdxǝ puɐ ɥɔʇɐM ˙˙˙sʞɹoʍ plɹoʍ ǝɥʇ ʍoɥ ʍouʞ noʎ ʞuᴉɥʇ no⅄,, pic.twitter.com/ZJOP7Vue0L— Marvel Studios (@MarvelStudios) October 5, 2016
7. When can I see it?
Doctor Strange is released in New Zealand on October 27.