LitCharts assigns a color and icon to each theme in The Once and Future King, which you can use to track the themes throughout the work.
Chivalry, Satire & Medieval Life
Fate (Time)
Quest and The Holy Grail
Might vs. Right
War
Summary
Analysis
It is dark in Gawaine's tent. He is lying facedown and crying in pain while Arthur strokes his head. He has been injured twice now by Lancelot in battle. They talk about England, about what it will be like to return home. The Bishop of Rochester enters, bearing a long letter for the King. He reads it and turns deadly pale. Rochester and Gawaine stop their prattle and ask Arthur what has happened. He tells them that Mordred has announced that Arthur is dead and proclaimed himself King of England. Mordred is also going to marry Guenever. Guenever accepted his proposal and then barricaded herself in the Tower of London, but managed to slip a letter out. Mordred is now laying siege to her with cannons. Gawaine and Arthur decide they must hurry home and lay to rest the feud with Lancelot.
Sir Gawaine has also matured since he was a young knight who could not control his temper. His grief for his brothers is strong, but we also see how he has been the victim of Mordred's manipulations. Upon hearing the news about Mordred, both Arthur and Gawaine realize they must immediately end their feud with Lancelot—seeing, now, Mordred's madness exposed.