Timon comes out of his cave and considers the sun and the earth. He hopes the sun breeds plagues, and that all of like nature will come to hate each other. He rages about flatterers, says all things of men are devious and villainous, that he abhors all society of mankind, and he hopes it comes to destruction. He digs for roots in the ground, and suddenly finds gold! Astonished to have found gold when he now needs it least, Timon speaks of the awful power of wealth, how gold, "this yellow slave" (IV.iii.34), makes or breaks religion, makes thieves into senators, and convinces aged widows to wed again. He orders the earth to behave normally, to hide the gold and reveal roots, and reburies the gold, while keeping some of it.
Then Alcibiades enters, with one prostitute on each arm. He doesn't recognize Timon at first, and asks him who he is. Timon introduces himself as Misanthropos, a hater of mankind. Alcibiades recognizes him, and asks him how he changed so much. Alcibiades offers his friendship, but Timon turns it down, saying that no man can promise friendship and genuinely perform it. Alcibiades says he would like to help Timon, but he has little gold to offer him, yet gives him a small amount. Timon turns it down, and Alcibiades promises to help him when he has sacked Athens.
Timon perks up at the mention of an assault on Athens. He gives Alcibiades gold to support his campaign, urging him to kill everyone, even old men, virgins, children, women or priests. Alcibiades takes the gold, but hesitates at taking his advice. The prostitutes ask for gold too, and he gives it to them, urging them to continue in their profession, spreading illness among all their patrons. He urges them to give diseases to the men of Athens, to bring all men to squalid deaths. Alcibiades and the prostitutes prepare to depart for Athens, and Timon says he hopes he never sees Alcibiades again. Alcibiades is surprised, saying he never harmed Timon. Yet Timon shoos him away.
Timon continues digging in the ground for edible roots, speaking with disgust of mankind. Then Apemantus enters. Timon curses him, but Apemantus absorbs his slights, noting that his recent change in fortune has made Timon unlike himself, while his former flatterers still live in silk-lined comfort, forgetting Timon ever existed. Apemantus says it's only fair that Timon has sunk to this, for his wealth was frittered away in generosity to unworthy people, all villainous rascals. Apemantus dares Timon to try to get the creatures of nature to flatter him now. Timon tells him to leave, but Apemantus says he loves Timon more now than ever before. Timon accuses him of flattering his misery.
Timon asks why Apemantus has come. Apemantus replies that he intends only to vex Timon. Apemantus says Timon has become a beggar by his own compulsion, and would gladly be a rich man again if he could. Timon has willed himself into misery, says Apemantus. Timon insists Apemantus's experiences have been different, since he was never in fortune's favor. If Apemantus had lived Timon's life, he would have wasted himself away without reaching respectability. But Timon was like an oak whose leaves blew off in one blast of wintry air, and now must nakedly bear misfortune. It's harder for him, he says, since he never experienced it before, but Apemantus is used to suffering. Why does Apemantus hate mankind, Timon asks, when men have never flattered him? If Apemantus curses anyone, it should be his father, who left him to be raised by a beggar woman. Timon urges him to leave, saying if he had not been born the most miserable of men, he would have been a hateful flatterer.
Apemantus asks him if he is done ranting, and offers him food. Timon tells Apemantus to go back to Athens. Timon continues cursing Apemantus, who observes that Timon has to be an extremist: "the middle of humanity thou never knewest, but the extremity of both ends" (IV.iii.300). Timon asks Apemantus if anyone ever loved him; Apemantus replies that only he himself has. Timon asks what Apemantus would do with the world, if he had the power. Apemantus says he would give it to the beasts, but Timon says that wouldn't help him, since there would be no beast that he could be that would not be subject to another beast. Apemantus says Timon has hit on something, as Athens has already become a forest of beasts.
Timon and Apemantus insult each other, and Timon throws a rock at Apemantus to try to get him to leave. Timon considers his epitaph, for his hopefully imminent death. He looks on his gold, remarks on its power to influence the actions of men, and hopes it will reduce mankind do the behavior of low beasts. But Apemantus predicts throngs will arrive to seek the gold soon. Apemantus sees bandits approaching, and takes leave of Timon.
The thieves speak among themselves, wondering how to get the gold from Timon. They approach Timon, saying they are soldiers. But Timon suspects they are thieves, and gives them gold, urging them on to do villainy to men, to steal money and take lives. Discoursing in thievery, Timon says the sun is a thief who robs the sea, the moon thieves from the sun, the sea steals its tides from the moon, and the earth is a thief, stealing its fertility from excrement. Everything is a thief, therefore, and everyone also. Timon sends the bandits to Athens, tells them to break into shops and steal as much as he has given them.
The thieves are impressed by his speech, so much so that Timon nearly convinces them to leave their profession than to go on stealing. They realize Timon advises them thus out of hatred for mankind, not out of enthusiasm for thievery. But they decide to head to Athens before giving up their trade, and exit.
Flavius arrives, speaking sadly about his fallen master. How vile is friendship, he says, that it has made Timon fall so far. When Timon sees him, he asks if he recognizes him. Timon says he has forgotten all men, so Flavius says he was once Timon's poor honest servant. Yet Timon says he had no honest men about him. Flavius insists his grief is honest, and Timon sees he weeps. Timon softens to Flavius, since his weeping demonstrates a sense of pity.
Flavius offers his money to Timon. Timon is astonished, and thinks that the kindness of his servant is nearly enough to make him change his mind about abandoning mankind. He admits that there is one honest man among the villains of the world, and he is but a servant. Timon would have hated all mankind, but one man escapes his curses. He says Flavius is more honest than he is wise, for by betraying Timon he could have found a much better job. And then he asks Flavius if his kindness is a plot, "A usuring kindness, and, as rich men deal gifts, / expecting in return twenty for one?" (IV.iii.501-2). Flavius insists that what he offers is real kindness and love, and he offers to take care of Timon's comfort in the wilderness. He says his only wish is to become rich so that he might make Timon rich again.
Timon gives Flavius money on the condition that he lives apart from mankind, that he never gives anything to even the skinniest beggar. Flavius begs to stay, but Timon sends him away.
Timon escapes Athens hoping to be left alone, but he has barely a moment to himself in the wilderness. He has just enough time to discover gold, an unfortunate irony for a man who has just been broken by an absence of gold. But Timon can't go back now, so he distributes the gold to those he believes can use it to bring about the downfall of Athens. He gives it to Alcibiades to help in his campaign against Athens and to the prostitutes to urge them to infect as much of the population as they can. He gives it to the bandits and urges them to rob Athens--but he makes them so rich that they consider quitting their profession! But overall he wishes destruction and ruin on his former home.
Even in the wilderness people line up for Timon's attention. Apemantus arrives, claiming he has come only to annoy Timon, and doing just that. Yet the two pause in their insult slinging long enough to have a reasonable conversation about their fates, how Timon's fall is harder because he had been raised so high. Yet the two men don't seem to come to any greater closeness through this exchange, even through a kinship of hating humanity. In the feast scene, Apemantus played the observer, but here he must interact with Timon--yet to what end? He achieves no understanding with Timon, and is the only character who leaves without any gold.
Then Flavius arrives, demonstrating to Timon that he had one honest man in his company in Athens, and convincing him that he need not curse the entire human race. Timon notes that this one honest man is a servant, not a lord or a senator or a man of any stature. But it's too late for Timon to benefit from this information; he gives Flavius his newly acquired gold and prepares to die. Yet Athens is redeemed, if not in Timon's eyes; for one good man among the masses may be enough to make Athens worth saving.