Loosely based on Nowra's own experience at producing a play (Trial by Jury) at Melbourne's Plenty Mental Home, Cosi has become a favourite with theatre companies and audiences alike since it premiered in 1992. Full of theatrical jokes and roles rich with Jonsonian humour, the play's use of a play rehearsal device also provokes images of the not-too dissimilar 'families' that come together in the professional theatre. Indeed, Nowra notes in the premiere season's programme notes that 'like the actual events of those days [the play] is, I hope, full of comedy and affection. Real madness and angst only occurred when I worked with professional actors'.
Set in 1971, Cosi takes an affectionate look at madness and mayhem in a world where institutions can be less limiting than ideology. The narrative is played out two locations, a mental institution and a suburban backyard. , Fresh from university, Lewis (a play on Louis) arrives to direct a play with the inmates, but is persuaded by Roy to stage his favourite opera, Cosi Fan Tutte. Lewis' problems don't end, however, with the fact that the other inmates are neither opera singers nor Italian-speakers. There is Ruth, troubled by the concept of a real illusion ; Zac, who insists on playing Wagner ; Doug, who is committed to the closed ward ; not to mention the sexual advances by Cherry and Julie. Lewis's world is no less complicated at home, where he has to contend with escaping pigs, exploding beer bottles and the pretensions of his politically correct friends.
The music incorporated into the narrative includes: 'Wild Thing' (by The Troggs), various songs from Cosi Fan Tutte, 'Purple Haze' (Jimmy Hendrix) 'Candy Says' (a Velvet Underground song, pre-recorded), and Wagner's 'The Ride Of The Valkyries'.