Nico and Maria, Maltese brother and sister, are separated when Nico is abducted by Moorish slavers. Taken to Algiers to be the personal slave of a wealthy merchant, he becomes a pawn in household politics and sets out to escape. Maria, stranded in Malta with unsympathetic parents, makes her own plans to escape the island and find her brother. She joins a group of Jews - forced by their Christian rulers to renounce their faith - who continue their rituals clandestinely. French aristocrat Christien de Vries yearns to prove himself as a surgeon in the Order of St. John, to which he was pledged as an infant but joined only as a result of a life-altering oath. These unforgettable characters find themsleves caught up in the sweep of history as the Ottomans confront the Knights in the historic Siege of Malta, and the fate of Europe hangs in the balance.