The second scene of the fourth act takes place before the Duke of Albany's palace. Goneril is not only cruel, but also depraved. She despises her husband and discloses her love to the villain Edmund, who has inherited the title of his father Gloucester. Edmund leaves, and a conversation takes place between Goneril and her husband. The Duke of Albany, the only figure with human feelings, who had already previously been dissatisfied with his wife's treatment of her father, now resolutely takes Lear's side, but expresses his emotion in such words as to shake one's confidence in his feeling. He says that a bear would lick Lear's reverence, that if the heavens do not send their visible spirits to tame these vile offenses, humanity must prey on itself like monsters, etc.

Goneril does not listen to him, and then he begins to abuse her:

 
"See thyself, devil!
Proper deformity seems not in the fiend
So horrid as in woman."
 

"O vain fool," says Goneril. "Thou changed and self-cover'd thing, for shame," continues the Duke:

 
"Be-monster not thy feature. Were't my fitness
To let these hands obey my blood,
They are apt enough to dislocate and tear
Thy flesh and bones; howe'er thou art a fiend,
A woman's shape doth shield thee."
 

After this a messenger enters, and announces that the Duke of Cornwall, wounded by his servant whilst plucking out Gloucester's eyes, had died. Goneril is glad but already anticipates with fear that Regan, now a widow, will deprive her of Edmund. Here the second scene ends.

The third scene of the fourth act represents the French camp. From a conversation between Kent and a gentleman, the reader or spectator learns that the King of France is not in the camp and that Cordelia has received a letter from Kent and is greatly grieved by what she has learned about her father. The gentleman says that her face reminded one of sunshine and rain.

 
"Her smiles and tears
Were like a better day; those happy smiles
That play'd on her ripe lip seem'd not to know
What guests were in her eyes; which parted thence,
As pearls from diamonds dropp'd."
 

And so forth.

The gentleman says that Cordelia desires to see her father, but Kent says that Lear is ashamed of seeing this daughter whom he has treated so unkindly.

In the fourth scene, Cordelia, talking with a physician, tells him that Lear has been seen, that he is quite mad, wearing on his head a wreath of various weeds, that he is roaming about and that she has sent soldiers in search of him, adding that she desires all secret remedies to spring with her tears, and the like.

She is informed that the forces of the Dukes are approaching, but she is concerned only about her father and departs.

The fifth scene of the fourth act lies in Gloucester's castle. Regan is talking with Oswald, Goneril's steward, who is carrying a letter from Goneril to Edmund, and she announces to him that she also loves Edmund and that, being a widow, it is better for her to marry him than for Goneril to do so, and she begs him to persuade her sister of this. Further she tells him that it was very unreasonable to blind Gloucester and yet leave him alive, and therefore advises Oswald, should he meet Gloucester, to kill him, promising him a great reward if he does this.

In the sixth scene, Gloucester again appears with his still unrecognized son Edgar, who (now in the guise of a peasant) pretends to lead his father to the cliff. Gloucester is walking along on level land but Edgar persuades him that they are with difficulty ascending a steep hill. Gloucester believes this. Edgar tells his father that the noise of the sea is heard; Gloucester believes this also. Edgar stops on a level place and persuades his father that he has ascended the cliff and that in front of him lies a dreadful abyss, and leaves him alone. Gloucester, addressing the gods, says that he shakes off his affliction as he can bear it no longer, and that he does not condemn them – the gods. Having said this, he leaps on the level ground and falls, imagining that he has jumped off the cliff. On this occasion, Edgar, soliloquizing, gives vent to a yet more entangled utterance:

 
"I know not how conceit may rob
The treasury of life when life itself
Yields to the theft; had he been where he thought,
By this had thought been past."
 

He approaches Gloucester, in the character of yet a different person, and expressing astonishment at the latter not being hurt by his fall from such a dreadful height. Gloucester believes that he has fallen and prepares to die, but he feels that he is alive and begins to doubt that he has fallen from such a height. Then Edgar persuades him that he has indeed jumped from the dreadful height and tells him that the individual who had been with him at the top was the devil, as he had eyes like two full moons and a thousand noses and wavy horns. Gloucester believes this, and is persuaded that his despair was the work of the devil, and therefore decides that he will henceforth despair no more, but will quietly await death. Hereupon enters Lear, for some reason covered with wild-flowers. He has lost his senses and says things wilder than before. He speaks about coining, about the moon, gives some one a yard – then he cries that he sees a mouse, which he wishes to entice by a piece of cheese. Then he suddenly demands the password from Edgar, and Edgar immediately answers him with the words "Sweet marjoram." Lear says, "Pass," and the blind Gloucester, who has not recognized either his son or Kent, recognizes the King's voice.

Then the King, after his disconnected utterances, suddenly begins to speak ironically about flatterers, who agreed to all he said, "Ay, and no, too, was no good divinity," but, when he got into a storm without shelter, he saw all this was not true; and then goes on to say that as all creation addicts itself to adultery, and Gloucester's bastard son had treated his father more kindly than his daughters had treated him (altho Lear, according to the development of the drama, could not know how Edmund had treated Gloucester), therefore, let dissoluteness prosper, the more so as, being a King, he needs soldiers. He here addresses an imaginary hypocritically virtuous lady who acts the prude, whereas and, saying this, Lear screams and spits from horror. This monolog is evidently meant to be addressed by the actor to the audience, and probably produces an effect on the stage, but it is utterly uncalled for in the mouth of Lear, equally with his words: "It smells of mortality," uttered while wiping his hand, as Gloucester expresses a desire to kiss it. Then Gloucester's blindness is referred to, which gives occasion for a play of words on eyes, about blind Cupid, at which Lear says to Gloucester, "No eyes in your head, nor no money in your purse? Your eyes are in a heavy case, your purse in a light." Then Lear declaims a monolog on the unfairness of legal judgment, which is quite out of place in the mouth of the insane Lear. After this, enter a gentleman with attendants sent by Cordelia to fetch her father. Lear continues to act as a madman and runs away. The gentleman sent to fetch Lear, does not run after him, but lengthily describes to Edgar the position of the French and British armies. Oswald enters, and seeing Gloucester, and desiring to receive the reward promised by Regan, attacks him, but Edgar with his club kills Oswald, who, in dying, transmits to his murderer, Edgar, Goneril's letter to Edmund, the delivery of which would insure reward. In this letter Goneril promises to kill her husband and marry Edmund. Edgar drags out Oswald's body by the legs and then returns and leads his father away.

 
"The fitchew nor the soiled horse goes to't
With a more riotous appetite.
All women inherit the gods only to the girdle
Beneath is all the fiend's" —
 

The seventh scene of the fourth act takes place in a tent in the French camp. Lear is asleep on a bed. Enter Cordelia and Kent, still in disguise. Lear is awakened by the music, and, seeing Cordelia, does not believe she is a living being, thinks she is an apparition, does not believe that he himself is alive. Cordelia assures him that she is his daughter, and begs him to bless her. He falls on his knees before her, begs her pardon, acknowledges that he is as old and foolish, says he is ready to take poison, which he thinks she has probably prepared for him, as he is persuaded she must hate him. ("For your sisters," he says, "have done me wrong: you have some cause, they have not.") Then he gradually comes to his senses and ceases to rave. His daughter suggests that he should take a walk. He consents and says: "You must bear with me. Pray you now forget and forgive: I am old and foolish." They depart. The gentleman and Kent, remaining on the scene, hold a conversation which explains to the spectator that Edmund is at the head of the troops and that a battle must soon begin between Lear's defenders and his enemies. So the fourth act closes.

In this fourth act, the scene between Lear and his daughter might have been touching if it had not been preceded in the course of the earlier acts by the tediously drawn out, monotonous ravings of Lear, and if, moreover, this expression of his feelings constituted the last scene. But the scene is not the last.

In the fifth act, the former coldly pompous, artificial ravings of Lear go on again, destroying the impression which the previous scene might have produced.

The first scene of the fifth act at first represents Edmund and Regan; the latter is jealous of her sister and makes an offer. Then come Goneril, her husband, and some soldiers. The Duke of Albany, altho pitying Lear, regards it as his duty to fight with the French who have invaded his country, and so he prepares for battle.

Then Edgar enters, still disguised, and hands to the Duke of Albany the letter he had received from Goneril's dying steward, and tells him if he gains the victory to sound the trumpet, saying that he can produce a champion who will confirm the contents of the letter.

In the second scene, Edgar enters leading his father Gloucester, seats him by a tree, and goes away himself. The noise of battle is heard, Edgar runs back and says that the battle is lost and Lear and Cordelia are prisoners. Gloucester again falls into despair. Edgar, still without disclosing himself to his father, counsels endurance, and Gloucester immediately agrees with him.

The third scene opens with a triumphal progress of the victor Edmund. Lear and Cordelia are prisoners. Lear, altho no longer insane, continues to utter the same senseless, inappropriate words, as, for example, that in prison he will sing with Cordelia, she will ask his blessing, and he will kneel down (this process of kneeling down is repeated three times) and will ask her forgiveness. And he further says that, while they are living in prison, they will wear out "packs and sects of great ones"; that he and Cordelia are sacrifices upon which the gods will throw incense, and that he that parts them "shall bring a brand from heaven and fire them like foxes; that he will not weep, and that the plague shall sooner devour his eyes, flesh and fell, than they shall make them weep."

Edmund orders Lear and his daughter to be led away to prison, and, having called the officer to do this, says he requires another duty and asks him whether he'll do it? The captain says he can not draw a cart nor eat dried oats, but if it be men's work he can do it. Enter the Duke of Albany, Goneril, and Regan. The Duke of Albany wishes to champion Lear, but Edmund does not allow it. The daughters take part in the dialog and begin to abuse each other, being jealous of Edmund. Here everything becomes so confused that it is difficult to follow the action. The Duke of Albany wishes to arrest Edmund, and tells Regan that Edmund has long ago entered into guilty relations with his wife, and that, therefore, Regan must give up her claims on Edmund, and if she wishes to marry, should marry him, the Duke of Albany.

Having said this, the Duke of Albany calls Edmund, orders the trumpet to be sounded, saying that, if no one appears, he will fight him himself.

Here Regan, whom Goneril has evidently poisoned, falls deadly sick. Trumpets are sounded and Edgar enters with a vizor concealing his face, and, without giving his name, challenges Edmund. Edgar abuses Edmund; Edmund throws all the abuses back on Edgar's head. They fight and Edmund falls. Goneril is in despair. The Duke of Albany shows Goneril her letter. Goneril departs.

The dying Edmund discovers that his opponent was his brother. Edgar raises his vizor and pronounces a moral lesson to the effect that, having begotten his illegitimate son Edmund, the father has paid for it with his eyesight. After this Edgar tells the Duke of Albany his adventures and how he has only just now, before entering on the recent combat, disclosed everything to his father, and the father could not bear it and died from emotion. Edmund is not yet dead, and wants to know all that has taken place.

Then Edgar relates that, while he was sitting over his father's body, a man came and closely embraced him, and, shouting as loudly as if he wished to burst heaven, threw himself on the body of Edgar's father, and told the most piteous tale about Lear and himself, and that while relating this the strings of life began to crack, but at this moment the trumpet sounded twice and Edgar left him "tranced" – and this was Kent.

Edgar has hardly finished this narrative when a gentleman rushes in with a bloody knife, shouting "Help!" In answer to the question, "Who is killed?" the gentleman says that Goneril has been killed, having poisoned her sister, she has confessed it.

Enters Kent, and at this moment the corpses of Goneril and Regan are brought in. Edmund here says that the sisters evidently loved him, as one has poisoned the other for his sake, and then slain herself. At the same time he confesses that he had given orders to kill Lear and to hang Cordelia in prison, and pretend that she had taken her own life; but now he wishes to prevent these deeds, and having said this he dies, and is carried away.

After this enters Lear with the dead Cordelia in his arms, altho he is more than eighty years old and ill. Again begins Lear's awful ravings, at which one feels ashamed as at unsuccessful jokes. Lear demands that all should howl, and, alternately, believes that Cordelia is dead and that she is alive.

"Had I your tongues and eyes," he says "I'd use them so that heaven's vault should crack."

Then he says that he killed the slave who hanged Cordelia. Next he says that his eyes see badly, but at the same time he recognizes Kent whom all along he had not recognized.

The Duke of Albany says that he will resign during the life of Lear and that he will reward Edgar and Kent and all who have been faithful to him. At this moment the news is brought that Edmund is dead, and Lear, continuing his ravings, begs that they will undo one of his buttons – the same request which he had made when roaming about the heath. He expresses his thanks for this, tells everyone to look at something, and thereupon dies.

In conclusion, the Duke of Albany, having survived the others, says:

 
"The weight of this sad time we must obey;
Speak what we feel, not what we ought to say.
The oldest hath borne most: we that are young
Shall never see so much, nor live so long."
 

All depart to the music of a dead march. Thus ends the fifth act and the drama.