Dead Ringers is a 1988 psychological thriller film starring Jeremy Irons in a dual role as identical twin gynecologists. David Cronenberg directed and co-wrote the screenplay with Norman Snider. Their script was based on the lives of Stewart and Cyril Marcus and on the novel Twins by Bari Wood and Jack Geasland, a "highly fictionalized" version of the Marcuses' story. The film won numerous honors, including for Irons' performance, and 10 Genie Awards, notably Best Motion Picture. Toronto International Film Festival critics have ranked it among the Top 10 Canadian Films of All Time.