Diane, a young woman growing up in Australia in the mid 1960s, walks away from her fiancé to join a convent after being sure she has a calling to the faith. The Catholic Church and its followers are struggling with huge changes. The Pope has died, there is war in Vietnam and mandatory conscription, there is the Vatican controversy on abortion and contraception, and the changing face of the Church as a whole. Told in six parts, Diane faces her own demons and has to finally decide if she can teach what the Church preaches, or if it's simply impossible for her to reconcile all the contradictions of the faith and uphold her vow of obedience.

Neal McBride is a Glasgow cop who likes to go undercover - the rest of the police wish he would stay there. When he arrests a politician he gets reassigned to where they used to send criminals: Australia. Lancelot Cooper is a Sydney cop but a country boy at heart; he is as trusting as McBride is suspicious. The two are partners on a case where death, deception and betrayal propels them into a desperate fight for survival.