Lothair, a wealthy young orphaned Scottish nobleman (loosely based on the 3rd Marquess of Bute) has been brought up in the legal guardianship of his Presbyterian uncle Lord Culloden and of a Catholic convert, Cardinal Grandison (based on H. E. Manning). When he comes of age Lothair finds himself the centre of attention of three fascinating women, Lady Corisande, Clare Arundel, and Theodora Campion, representing the Church of England, the Roman Catholic Church, and the Radical cause respectively. Wavering in his allegiances, he unsuccessfully proposes marriage to Lady Corisande, almost joins the Catholic Church, and finally joins Theodora in Italy as a volunteer in the army of Garibaldi, which is fighting to take the Papal States for Italy. Theodora is killed at Viterbo, and Lothair is seriously wounded at the Battle of Mentana, but is nursed back to health by Clare Arundel, who tries to persuade him that he was saved by an apparition of the Virgin Mary. He takes refuge with the