Cosi is a musical drama film that follows the story of a man's journey in directing a musical. Lewis Riley (Ben Menelsohn) applies for a job at a mental hospital to become a drama teacher. He quickly gets the job and is put in charge of directing Cosi Fan Tutte, an opera by Mozart. The first problem Lewis faces is that the play is in Italian, and the patients who will star in the play speak only English. The next problem he has is with of one of the patients, Roy (Barr Otto), who criticizes Lewis's job and takes it upon himself to cast characters in the play. Meanwhile, in his personal life, Lewis is having problems with his girlfriend, Lucy (Rachel Griffiths). These problems are made worse when his friend, Nick (Aden Young), starts to put the moves on Lucy. Watch Cosi to find out what happens to Lewis' personal and professional life.