Prometheus now announces yet again that he knows how Zeus will eventually fall from power, fulfilling the curse of his father, Cronus. The Chorus warns Prometheus that Zeus may make his punishment even more severe if he continues in his defiance, but Prometheus does not care.

Hermes, the messenger of the gods, arrives. He tells Prometheus that Zeus has sent him to find out more about who is destined to overthrow him. But Prometheus is not impressed: He has already seen the two previous rulers of the gods fall from power and knows that Zeus will suffer the same fate. In a combative exchange, Prometheus tells Hermes that he is no better than a slave and declares that he hates “all of the gods / that unjustly returned [him] ill for good” (975-76). Hermes responds that Prometheus is “mad” (977).

Finally realizing that Prometheus will not tell him what he wants to know, Hermes resorts to threats: If Prometheus does not reveal what he knows, Zeus will bury him beneath the mountain for “a vast extent of time” (1020), after which Prometheus will emerge only to find that Zeus’s eagle has been sent to devour his liver every day.