Zero Hour traces Zero Mostel’s early days growing up on Manhattan’s Lower East Side as the son of Orthodox Jewish immigrant parents. It follows his rise as a stand-up comedian from the Borscht Belt to Manhattan’s most exclusive supper clubs and his journey from the devastation of the blacklist to his greatest Broadway triumphs, most notably as Tevye in Fiddler on the Roof. It also shows him working through his love-hate relationship with Jerome Robbins.