Early spring 1944. Army Captain Charles Ryder transports his company to brigade headquarters at a secret location. After an exhausting journey, they arrive at the new camp, Brideshead Castle, the site of bittersweet memories for Charles.

Back at Oxford, Charles and Sebastian fall into a funk. The Lady enlists Charles to watch over wayward Sebastian, but Sebastian continues his drunken revelry. A crisis is narrowly averted, while Sebastian's mood continues to grow darker.