In a farmhouse adjacent to the castle, Gloucester settles Lear in and promises to return shortly. Kent notes to Edgar that Lear's wits have entirely "given way to his impatience."
What follows is the mock trial. Lear convenes a court. He appoints Edgar, still performing as Poor Tom, as "most learned justicer," the Fool as his "sapient" colleague, and Kent as a commissioner. The defendants are Goneril and Regan. Lear speaks with the full authority of someone who believes every word he is saying: "I here take my oath before this honourable assembly, she kicked the poor King her father." The Fool addresses the empty space where Goneril should be, then says he has mistaken her for a joint-stool. Regan flees, in Lear's mind, and he screams for swords and fire: "Corruption in the place! False justicer, why hast thou let her 'scape?"
Edgar watches from inside his disguise. The performance is becoming harder to maintain: "My tears begin to take his part so much / They mar my counterfeiting."
The trial subsides. Lear asks the question the whole scene has been building toward: "Is there any cause in nature that makes these hard hearts?" He receives no answer. His mind slides. He tells Kent to draw the curtains. "We'll go to supper i' the morning." The Fool responds: "And I'll go to bed at noon." It is the Fool's last line in the play.
Gloucester returns with urgent news: a plot against Lear's life has been overheard. They must move immediately toward Dover. Lear, exhausted past resistance, is carried out.
Edgar is left alone and speaks the chapter's final reflection. Watching the king's collapse has changed something: "How light and portable my pain seems now, / when that which makes me bend makes the King bow." He sees the parallel plainly, "he childed as I fathered", a father betrayed by his children, a son betrayed by his father. Suffering shared across that mirror does not disappear, but it becomes, for a moment, more bearable.
He goes back to hiding. "Lurk, lurk."
