Edmund's gibberish about foul fiends certainly fits both Edgar and Lear's circumstances, since both have been victims of deceit and wickedness. Once they all come in out of the storm, Lear abandons his plans for seeking physical revenge, and instead, decides to place Goneril and Regan on trial. The audience might consider a mock trial as further evidence of Lear's madness; but a trial is typically a search for the truth — and, often, a search for the motive or reason for an action. Lear, like so many victims, needs to know why this tragedy has happened. Did he deserve such abuse from his daughters? Did his actions contribute in some way to their evil attitudes? To Lear, gaining a grasp of the truth may lead the way to restoring his sanity.
Lear appoints the disguised Edgar and the Fool as judges, and begins the trial of Goneril, whom Lear accuses of kicking him. But the blow Goneril gave to her father was not physical; her injury was to his heart and soul. Lear urges the judges to "anatomize Regan, to see what breeds about her heart" (III.6.74–75). Lear's words are pointed and painful. Edgar cannot continue to participate, and even the Fool falls silent. Finally, Lear is so exhausted by the strain of the mock trial that he decides to pause for a much-needed rest.
This is the last appearance of the Fool. In his final line, he predicts his death: "I'll go to bed at noon" (III.6.83). The play never reveals whether the Fool actually dies, since the lines in Act V Scene 3 — "And my poor fool is hang'd" (V.3.304) — refer to Cordelia's death. The Fool has fulfilled his role, stepping in to take Cordelia's place after her banishment and disappearing as she reappears. Both Cordelia and the Fool are caretakers for Lear, and when one is present, the other need not be.
Lear and his allies heed Gloucester's warning that the king must flee to Dover. With the king and his forces gone, Gloucester is left alone to face Cornwall's wrath. After Gloucester also exits, Edgar is left alone on stage. His soliloquy ties together the two parallel plots and points to the similarities between his situation and that of the king's: "He childed as I father'd!" (III.6.108). The king has cruel children, while Edgar has a cruel father, but Edgar realizes his situation is insignificant compared with that of the king, who has lost both his rule and his mind.
