Prometheus gets chained to a barren rock in Scythia for the very, very minor crime of stealing fire from the gods and giving it to humans.
Various characters show up and try to convince Prometheus to submit to the authority of Zeus. Prometheus refuses, because he knows that Zeus will father a child more powerful than he is, who will kick him off his throne. And that child? Descendant of Io. So Prometheus isn't feeling much like submitting, thankyouverymuch.
Hermes comes and tries to convince Prometheus to reveal more details about Zeus's destiny. Prometheus refuses. A huge storm (presumably sent by Zeus) starts brewing. The earth opens up and Prometheus falls into a chasm.