When it came to signing up for Captain America: Civil War, Daniel Brühl lets his feelings be known in no uncertain terms. 'I was shit scared,' he grins. The amiable soft-spoken star is hardly a newbie. He’s been acting for 20 years, including roles for Quentin Tarantino (in his WWII saga Inglorious Basterds) and Ron Howard (playing Austrian racing driver Niki Lauda in Rush). But there was something about the scale of a Marvel movie that left his jaw hanging.

'I became a 12 year-old boy again when I stepped on set,' he admits. 'Once you’re there, you’re aware that it’s really even bigger than you thought it would be.' Sitting in London’s Corinthia Hotel, he tells stories about being invited for lunch by Iron Man star Robert Downey Jr to his 'village' of trailers and watching crew members perform jobs – that usually involved 'measuring things with a tennis ball' – that he didn’t understand. 'That’s so freaky,' he laughs, 'it already puts you in a parallel universe!'

Even by Marvel standards, Captain America: Civil War is enormous. Inspired by the 2006-2007 comic series written by Scotland’s own legendary Mark Millar, it sees the Avengers at odds with each other after a law is passed to regulate the superhero team under the guidance of the UN. Pitting Chris Evans’ Captain America against Iron Man, the film reunites nearly all of the characters, and introduces one or two new ones, as they take sides in this titanic superhero smackdown.

As for Brühl, he plays the rather shady Zemo, a German-accented mystery man who has his own motives for watching the Avengers tear themselves apart. Somewhat different to the purple-masked villain in the comics, Brühl’s point of reference was Kevin Spacey’s string-pulling serial killer in Seven. 'What my character does is pretty smart and clever and that’s what I liked about it – he tries to destroy them from within. It’s an idea that I liked.'

He calls it 'a no-brainer' joining up with Marvel, though stops short of admitting he’s now about to step on the Hollywood carousel for further franchise films. 'It would depend. I wouldn’t say categorically "no" and not "yes" either. If the script is totally stupid, then I wouldn’t. But many of these films are very well done. And in the case of the Marvel films, I cannot think of one that was bad. It’s entertainment on the highest level.'

Whether he returns to Europe or stays in Hollywood, it represents another remarkable red-letter moment in the 37 year-old Brühl’s already-eclectic career. Born in Barcelona, to a Spanish mother and a German father, and raised in Berlin 'in a very multicultural environment', he is as pan-European as they come. He speaks English, German, Spanish and French, and has acted in all four languages. 'My dream was always to work in different places,' he says.

With a family entrenched in the arts – his uncle worked in radio, a cousin directs theatre, his sister is a documentary producer – Brühl’s passage was assured. His late father Hanno Brühl was a filmmaker, and Brühl worked with him when he was 19 on the 1999 TV movie Hin und Weg. His breakout movie came four years later, with Goodbye Lenin!, the BAFTA and Golden Globe nominated tale set just after the fall of the Berlin Wall. It was an 'explosive and overwhelming' experience', he says. 'For me, the real kick-off.'

A year later he was acting with Judi Dench and Maggie Smith in Ladies in Lavender and he hasn’t looked back, effortlessly gliding from blockbusters like The Bourne Ultimatum to prestige dramas like Anton Corbijn’s A Most Wanted Man and Michael Winterbottom’s The Face of an Angel. The only problem now is the demands on his time. After a year on the road, he’s tired. 'I realized I want to spend more time at home and spend more time in Berlin and Barcelona.'

Around Captain America, Brühl has completed forthcoming WWII-set dramas, The Zookeeper’s Wife, with Jessica Chastain, and Alone In Berlin, with Emma Thompson. Then there’s Colonia, with Emma Watson. Due out in the UK in July, it tells of Colonia Dignidad, a real-life sect in the south of Chile during the Pinochet regime. Brühl plays a German citizen kidnapped into the cult, which became notorious for acts of sexual abuse on minors.

'It was tough,' he admits. 'It was not an easy one. It’s quite a dark chapter in Chilean – and also German – history.' Brühl and Watson spent time with a victim who had lived in the sect. 'If you listen to him, you’re aware that we didn’t only do a film, but you’re telling a real story … then it touches you, undeniably.' Did it leave him scarred? He shakes his head. 'I very rarely felt this famous "hole" that some actors talk about. I’m able to digest and to get over it.' But he knows what he needs next: 'A romantic comedy.'

Captain America: Civil War opens in cinemas on Fri 29 Apr; Colonia is released on Fri 1 Jul.