Catherine feels optimistic about peaceful coexistence with Peter and their increasing chemistry. When smallpox breaks out in the servant’s quarters, however, Peter reverts to his old ways. Meanwhile, Leo and…

Catherine and Peter are co-parenting their newborn son, Paul, with the help of Elizabeth and trying to avoid their feelings for each other. When Paul goes missing, Peter and Catherine…

Adam and Zaf try to find a group of terrorists who have infiltrated Britain. Ros oversees a visit by a delegation of Saudi princes offering a guaranteed oil supply in…