KEIRA Knightley has said she signed up to new thriller Jack Ryan: Shadow Recruit because she was tired of playing the tragic heroine.
The British actress stars opposite Chris Pine in the action movie, based on novelist Tom Clancy's CIA agent hero and directed by Kenneth Branagh.
Knightley's recent film roles have included the lead in Anna Karenina, who commits suicide over a broken heart, Russian psychoanalyst Sabina Spielrein, who was murdered by Nazis, in A Dangerous Method, and in Never Let Me Go she played a clone created for the purpose of having her organs harvested.
Knightley revealed at a press conference in London: "I think when I finished doing Anna Karenina I realised that I'd been playing characters that pretty much died for about the last five years and I fancied doing something fun."
Shadow Recruit is an origins film of the Jack Ryan character, and sees him recruited into the CIA just as he begins a relationship with his physiotherapist, Cathy Muller, played by Knightley.
The actress said she was interested in the film's exploration of how a secret agent might balance a relationship with a life of espionage.