Edmund orders that the captured Lear and Cordelia be taken away to prison. Cordelia, speaking with Lear, wonders if they should ask to see Goneril and Regan. But Lear, delighted to be with Cordelia again, says no. He says that they will enjoy prison, where they can laugh and sing and tell old stories and mock the courtiers and their petty political gossip. He says that in prison they will live longer than "hordes" of rulers who will come and go on the whims of fortune. They exit. As they go, Edmund calls back a Captain, one of the soldiers accompanying them and hands him a letter, instructing him that if he kills Lear and Cordelia he will gain "noble fortunes" (35). The Captain says that he will do it.
Reunited with Cordelia, Lear seems to see prison as offering the same kind of opportunity that he thought he would get by giving up power: an escape from political responsibility that will let him stand outside the usual rules of the court and be amused by it. Yet Lear's idea is based on an assumption that, as tradition and custom dictates, Edmund will treat his prisoners well until they can stand trial. But Edmund cares only about power, not tradition, and he plays off the greed and ambition of others, such as the Captain, to corrupt them too.
Albany, Goneril, Regan and other soldiers enter to the sound of a flourish from a trumpet. Albany asks to have Lear and Cordelia brought to him so that they can be protected until they can be judged. Edmund explains that he has already sent them off. Albany reminds Edmund that he does not think of him as a brother, yet, but merely as an ally in the war. Regan interjects that she will give him herself and her property—all he requires to become Albany's brother. Goneril interjects that Regan should not get ahead of herself, and the two descend into squabbling, which Regan cuts off only because she feels sick to her stomach. In brief, she tells Edmund that he can take her soldiers, prisoners, and inheritance; she here makes him her "lord and master" (92).
Albany attempts to stand up and preserve the just order of law, which Edmund has just violated in his instructions to the Captain to kill Cordelia and Lear illegally. Meanwhile, personal conflict between Regan and Goneril pushes all onstage further toward disorder and destruction. Regan, boldly trying to seize Edmund from Goneril, completely abrogates their former sisterly bond.
Albany cuts all off when he announces that he is placing Edmund, as well as Regan, under arrest for capital treason. Albany calls for his men to let the trumpet sound and throws down his glove: if no one appears to fight with Edmund, in order to avenge his treasons, Albany vows that he himself will do so. As this is going on, off to one side, Regan grows increasingly sick. Goneril remarks to herself that Regan had better be sick—Goneril herself has poisoned her out of jealousy over Edmund. Denying that he is a traitor, Edmund accepts the challenge, throwing down his glove, as Regan is helped to exit.
While Albany is setting the stage for Edgar's revenge on Edmund, he is also living up to his vow in 4.2 that he would avenge Lear's suffering and Gloucester's lost eyes. His gesture, undertaken out of a sense of desire to guarantee just order by his authority, takes place just as the subplot between Goneril and Regan comes to a head, breaking their sisterly bond forever.
A herald reads a declaration calling for any man who would like to declare that Edmund is a traitor to come forth. He sounds the trumpet three times. On the third sounding, Edgar enters, armed (with his face covered). He refuses to identify himself: he has lost his name, he says, because of treason. Yet, he says, he is noble and will fight to prove Edmund a traitor. Edmund accepts. They fight. Edmund is wounded. When Edmund falls, Goneril becomes hysterical, cursing Edmund because he was not obligated by the laws of war to accept a challenge from an unknown assailant. Albany cuts her off, brandishing the letter that she wrote to Edmund, plotting against his life. Goneril shuts him up, reminding him that political power is hers, not his. She exits. Noting that she seems hysterical, Albany sends a soldier after her.
Edgar initially obscures his identity because he feels le lost it, when he was disinherited by his father and forced to take on the vagrant character of Poor Tom. With Edgar's rightful revenge on Edmund, the tides start to turn from the lowpoint (where Cordelia and the French lost their battle) back toward a restoration of just order in England. It is ironic that Edmund is killed because he himself is deceived by a disguise, and does not recognize his brother Edgar as his challenger.
Encouraging the fallen Edmund to "exchange charity" (200) with him, Edgar then identifies himself, concluding that "the gods are just, and of our pleasant vices/ Make instruments to plague us" (204-5), observing that Gloucester was punished for his adultery with Edmund's mother by the loss of his eyes. Edmund agrees: "the wheel is come full circle" (209). Edgar then explains everything that happened. He finishes by describing how he revealed himself to his father only right before leaving to fight Edmund. Gloucester, unable to bear his mixture of joy and grief, died on the spot. Edgar adds that Kent came upon them, as Gloucester was dying, and revealed himself as having served Lear in disguise, all this time.
Edgar, after revealing himself and ending the deception of his disguise, invokes the gods to explain that all the suffering that has happened is part of a just order that has now restored him to his rightful place. Edgar's revelation of Kent's identity furthers the process of unveilings that need to take place before all characters gain insight into everything that the audience (or the gods as divine spectators) have seen.
As Edgar is wrapping up his story, a Gentleman runs in, crying for help, with a bloody knife. He exclaims that he has just taken it from the heart of Goneril—who, after confessing to having poisoned Regan, committed suicide. Edmund confesses that he had pledged to wed both, and that now all three will be united in death. Albany orders the Gentleman to bring in the bodies. As he speeds off to do so, Kent arrives asking to see Lear. Reminded, Albany asks Edmund where Lear and Cordelia can be found. Edmund, saying he would like to do some good before he dies, orders them to send someone quickly to the king and his daughter—for he has written instructions for his Captain to kill them (earlier in 5.3). Edmund gives the messenger-soldier his sword, as a sign of the authenticity of the message. He explains that he instructed his soldier to hang her, and make it look like suicide, as Albany orders that he be carried off.
However, before order can be restored, the destruction and annihilation that has been unfolding ever since Cordelia's first speaking "nothing" has more to wreck in its path. With Edmund's confession that he pledged himself to both Goneril and Regan, the audience and the other characters see what poisoned their allegiance as sisters. Edmund also reveals the danger that Lear and Cordelia have been in, all while Albany and others believed them to be under the protection of law, awaiting judgment…
At this moment, Lear enters with Cordelia's body in his arms, crying: "Howl, howl, howl […] she's gone forever" (309-11). Although, he explains, half-mad, he killed the man who hanged her, he did so too late to save her. Then, seeing Kent, he asks, confused, who he is, noting that his "eyes are not o' th' best" (337). Kent identifies himself and explains that he has been serving Lear, in disguise as his servant Caius, all this time. Kent also reports to Lear that his two other daughters have committed suicide, but Lear does not seem to understand. Albany quiet Kent, pointing out that it is no use to attempt to explain such things to Lear now.
Lear is so devastated to be confronted with the loss of his one loyal child—a loss that ultimately resulted from his own misjudging her at the beginning of the play—that he can hardly process the fact that his entire family has now been annihilated. His confusion upon seeing Kent revealed, like his confusion upon waking up and being reunited with Cordelia in 4.7, reminds the audience that he is half-mad.
A messenger enters, reporting that Edmund is dead. Albany brushes off this "trifle" (359), then declares that, for the duration of Lear's life, they will return absolute power to him and all will be rewarded or revenged upon, according to their behavior. Lear, however, descends into raving with grief over Cordelia: "Why should a dog, a horse, a rat have life,/ And thou no breath at all?" he asks. "Thou'lt come no more,/ Never, never, never, never never" (370-2). He faints with grief; as he does, Kent prays that Lear's heart break, finally releasing him. Lear dies.
Albany proves that he is truly just and dutiful toward his father in law, insofar as he is willing to return power to him. However, the destruction has clearly gone too far for such a restoration of the order of pre-divided Britain. Lear's irrational raving about animals suggests a crazed sense of injustice; his full line of 'nevers' suggests that he cannot see meaning in anything anymore, and he seems to embrace death as an escape.
Albany orders that the corpses on stage be carried away, so that all can begin their general mourning. He then tells Kent and Edgar that they will rule over and rebuild Britain. Kent, however, says that he, too, must soon commit suicide in order to rejoin his master. Edgar announces that they all must learn the lessons of these sad times, "to speak what we feel, not what we ought to say." He concludes: "The oldest have borne most. We that are young shall never see so much nor live so long" (393-4).
Albany seeks to restore order to the kingdom by having Kent and Edgar, the only two characters remaining to have acted nobly through the play, take leadership of Britain. Kent's sense of duty remains so strong, however, that he cannot live without Lear, his master. Yet that does leave Edgar, who's inheritance was almost stolen from him by Edmund, to now rule over Britain. And Edgar, in taking power, pronounces an end to disguise or subterfuge in saying that all should speak what they feel and not what they think they should say, while also restoring a sense of order through his reverence for the older generation that was so abused by the younger, and which has now passed away.