Viggo Mortensen as Sigmund Freud. It's a casting that has raised more than a few eyebrows. In fact, the first eyebrow raised was Mortensen's own.
A Dangerous Method is David Cronenberg's historical film about the triangular, sexually charged relationship between Freud, his acolyte Carl Jung (Michael Fassbender) and patient-turned-psychotherapist Sabina Spielrein (Keira Knightley). It's the third time out for the director and Mortensen.
And it almost didn't happen.
Mortensen had been approached for the role of Freud, and admits he was initially skeptical. "If another director had offered it to me, I'd say, 'That's a bit of a stretch, I'm not sure about that.'
"And then I became unavailable, and it didn't matter. I had some family health matters to attend to and couldn't get free for more than a year. I said, 'Well, it was an interesting idea, kind of different but I can't do it.' "
Then, in a series of events that Jung might have defined as "synchronicity," Mortensen's replacement, Christoph Waltz decided to jump ship just before production, for a bigger paycheque on the movie Water For Elephants.
"That left David in a bit of a lurch," Mortensen recalls. "He had to cast someone who was right for the part in his mind, and also bankable, in a hurry.
"So he wrote me and said, 'Look, I know you might still not be available, but I have to ask, since you were the first choice. He said, 'I can compress your schedule, so what do you think?'
"And I said let's do it. And then, it was all about being terrified. It was, 'OK, I've got to do this now.' "
Bolstered by Cronenberg's confidence, Mortensen's approach to becoming the Father of Modern Psychiatry was from the outside in.
"I had to work on that with Stephan Dupuis, David's longtime makeup artist. He needed to have brown eyes because there are many written references to Freud's penetrating brown-eyed gaze.
"We had to do that and do things with the hairline, things like that. After that, it was more like, 'What's the essence of the person?' Y'know, I had a preconceived idea of Freud being very stiff, very formal, a wizened old man, very rigid personality. And he was anything but. He was very gregarious. Great conversationalist.
"He's someone who lived by his wits. Jews in Vienna and in Europe at that time, you had to be good with wordplay to get around the strong anti-Semitism and censorship. You had to think on your feet."
A script-heavy movie that encompasses three relationships at once (including Jung's arguably unethical sexual relationship with his patient Spielrein), A Dangerous Method, "could have made for a very dull and talkie movie, and David was very bold to take it on," Mortensen says.
"He approached it as if to say, I've been making movies based on these things for years. So his approach was, 'I'm going to approach this like any story. It's a universal story about people who are in competition, who are jealous, who are insecure, who are unfaithful, who manipulate, seduce, love each other, lust for each other.
"These are important subjects and important people and this is an important movie."
In the end, he says, Cronenberg was right. Mortensen "totally" felt like Freud. "It helped a lot of study, to go there (Vienna) and walk around.
There's a difference between being Viggo the Tourist and being Sigmund Freud, visiting and walking around in the same places he walked as Sigmund Freud, imagining yourself to be him. Going into antiquarian bookshops and finding things that were in his library. It's a different way to travel. And travelling is my favourite thing to do."
The Cronenberg/Mortensen connection didn't end with the final day of shooting. The multilingual actor's next job was in Argentina, where he played twins in Ana Piterbarg's Everybody Has A Plan.
"I played twins, and David of course had done that before (with Jeremy Irons in Dead Ringers), so I asked his advice. Technically, I wanted to know what was the easiest way to approach scenes where they're speaking to each other.
"He just sort of confirmed the approach I was taking. He talked about different shading, physical things, where their weight is placed, who their characters are. I was really asking a bunch of these things because it was a first-time director with a very low budget."
Cronenberg was also there in spirit when Mortensen was cast as Bull Lee (a thinly veiled caricature of William Burroughs) in the yet-to-be released movie of Kerouac's On The Road by Brazilian director Walter Salles.
"When I read the book, the last person I'd have seen myself playing would have been the Burroughs character," Mortensen says. "I was a little surprised. But it was just when I was finishing A Dangerous Method, and I thought, 'Don't forget, you were surprised at David's idea of you playing Freud too.' "