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.