O'Brien's theatrical output was unsuccessful. "Faustus Kelly", a play about a local councillor selling his soul to the devil for a seat in the Dáil, ran for only 11 performances in 1943. A second play, "Rhapsody in Stephen's Green", also called "The Insect Play", was a reworking of the Capek Brothers' synonymous play using anthropomorphised insects to satirise society. It also was put on in 1943 but quickly folded, possibly because of the offence it gave to various interests including Catholics, Ulster Protestants, Irish civil servants, Corkmen, and the Fianna Fail party. The play was thought lost, but was rediscovered in 1994 in the archives of Northwestern University.