COSI'Nowra has written a terrific play about theatre, madness, illusion, sanity, life: it's a big, splendidly Australian epic. Frank Gauntlett, Telegraph MirrorSet in 1971, Cosi is Louis Nowra's second semi autobiographical play. Lewis has recently left university and takes up a job in a mental institution directing Mozart's Cosi Fan Tutte. Lewis, the non participant, becomes emotionally involved with his actors' lives as his operatic production lurches