Keira Knightley says working with Kenneth Branagh on 'Jack Ryan: Shadow Recruit' was ''psychotic''.

The 28-year-old actress plays male lead Jack Ryan's fiance Cathy Muller in the forthcoming film and was thrilled to work with the 53-year-old ''actor/director'' who played a veteran of the Soviet invasion of Afghanistan, Viktor Cherevin, while he simultaneously controlled the artistic and dramatic aspects of the picture.

Talking to BANG Showbiz at the European premiere of the film at the Vue cinema in London's Leicester Square, she said: ''It was completely psychotic! I just wanted to see how it's done, because I've never worked with an actor/director before, and it's mad!

''There's another scene where he kidnapped me and he's being pretty horrific. He's screaming in my ear and threatening to kill me and all of a sudden he goes, 'OK, and cut! And thank you so much, ladies and gentlemen.' Suddenly he was this lovely Ken again. That's mad!

''The major reason to do this was to work with him, so being in a scene like that where it's just him and we're around a dinner table - and he's directing it as well - it's just fascinating.''

Knightley - who has recently starred in 2012's romantic drama 'Anna Karenina' and 2011's historical film 'A Dangerous Method' - was enthralled by the script and was excited about accepting the project when she knew Branagh would be working alongside her.

She added: ''I couldn't put it down. I think that's important with a thriller. I think I've done one other thriller, but not for a very, very long time. They're difficult to do because you need a proper storyteller to do them and Ken Branagh is a proper storyteller, so I thought this could be fun.''