Sebastian and Charles borrow Hardcastle’s car to travel to Brideshead. They stop to eat lunch outside, and Sebastian comments that he wishes he could bury a pot of gold everywhere he’s ever been happy, so he could come back and dig it up later when he’s "old and miserable."
We’re introduced to Sebastian’s teddy-bear, Aloysius.
Flashback to Sebastian puking into Charles’s first floor rooms and then having him over for lunch to repent.
Sebastian introduces Charles to all his friends, including Anthony Blanche.
Cut back to the first visit to Brideshead. Sebastian introduces Charles to Nanny Hawkins. He insists that they leave before Julia returns, and they in fact pass her on the road as they’ve leaving.
Sebastian reveals that he doesn’t like his family.
Over Easter vacation, Sebastian sends letters "written in remote fantasy" to Charles.
When Charles tries to confirm Anthony’s description of Sebastian and his family, Sebastian denies it and discusses his bear, as Anthony predicted he would.
Sebastian sends a letter to Charles that he is gravely ill. It turns out that he tripped over a croquet hoop and broken a tiny bone in his foot.
Sebastian and Charles spend all summer at Brideshead together drinking old wine. They also paint the interior of the office room together.
Sebastian has Charles draw the fountain at Brideshead and give it to Nanny Hawkins.
Sebastian debates religion with Charles. Sebastian’s beliefs are based on aesthetics.
Sebastian introduces Charles to his sister, Cordelia.
He takes Charles to Venice to visit his father and his mistress Cara.
The next year at Oxford, Sebastian gets several talking-tos from Monsignor Bell and Mr. Samgrass, both friends of his mothers.
Sebastian retreats into solitude, booze, and disliking Mr. Samgrass.
Sebastian, Charles, and Boy accept Rex’s invitation to go to the ball. Then the three men sneak out to party at Ma Mayfield's. They are arrested for drunk driving. Mr. Samgrass testifies on Sebastian’s behalf, but the incident is all over the newspapers.
Back at Oxford, both Sebastian and Charles are gated.
Sebastian resents his mother’s attempts to befriend Charles over the course of the Christmas vacation.
Sebastian asks Charles to take him away; they go to London together to stay with Charles’s father.
Back at Oxford, Sebastian continues to drink uncontrollably.
At Brideshead for over Easter, Sebastian makes a spectacle of himself and leaves Charles at the estate alone with his family.
When Charles finds Sebastian again in London, Sebastian asks if he’s taken Lady Marchmain’s side. Charles responds that he is with Sebastian, against the world.
They return to Oxford and Sebastian is more depressed than ever. His mother wants him to live with Monsignor Bell for the year, and ultimately takes him away from Oxford.
Sebastian stays with his father in Venice for a bit. He then travels through Europe with Mr. Samgrass as a chaperone.
Next Christmas Sebastian returns to Brideshead. It soon becomes clear that he gave Mr. Samgrass the slip and went on an extended drinking binge.
Lady Marchmain instructs the servants not to give Sebastian alcohol. He manages to sneak some anyway. He convinces Charles to give him money and during a family hunt runs off to a hotel bar.
After Charles leaves Brideshead, Sebastian gets his little sister Cordelia to slip him booze. In desperation his mother sends him off to Zurich with Rex to try and fix that whole alcoholism thing.
Through Anthony, we find out that Sebastian went to stay with him in France. He drank all day long and stole to finance his alcoholism. He’s now taken up with a German sergeant in French Morocco.
Charles finds Sebastian ill in Morocco. He seems unconcerned that his mother is dying and is too sick to travel to say good-bye anyway. He tells Charles that he enjoys taking care of Kurt, since his whole life people have been taking care of him.
Sebastian reports on Sebastian. Kurt is dead and Sebastian had traveled to Tunis and begged himself into a monastery there. She predicts that he will spend the rest of his life trying to be holy and occasionally lapsing into bouts of drinking. She doesn’t think this is too bad of a deal for her brother.