The Polish Pope is dead, and the cardinals are gathering to choose his successor. Finally the choice is left to two cardinals whose association goes back many years. In the mid 1930s, New Zealander Brendan Lehane and Spaniard Tomas Aquino had been young priests together, but both became involved in dangerous political activities, Brendan with a secret Catholic organisation, the Societa di Prodigaliti, and Tomas in Spain during the Civil War.
Brendan is sent on a dangerous mission to Abyssinia, and what happens there is to have a profound effect on his life. Tomas risks all in Spain, and falls in love with a beautiful young doctor. Their actions will cause papal displeasure and political instability, as the fascist forces gather strength and the Vatican struggles to maintain its honour.