Knightley starred in a 2011 revival of "The Children's Hour" by Lillian Hellman at the Comedy Theatre in London. Knightley's only film of 2011 was David Cronenberg's historical drama "A Dangerous Method", co-starring Viggo Mortensen, Michael Fassbender, and Vincent Cassel. Based on writer Christopher Hampton's 2002 stage play "The Talking Cure" and set on the eve of World War I, the film depicts the turbulent relationships between fledgling psychiatrist Carl Jung, his mentor Sigmund Freud and Sabina Spielrein. Knightley portrayed Spielrein, the troubled but beautiful young psychoanalyst who comes between Jung and Freud. The costume film premiered at the 68th Venice International Film Festival to a positive reception, while Knightley earned generally favourable reviews by critics, with Andrew O'Hehir of "Salon" noting her "the real star of this film".