The play is composed almost entirely of speeches and contains little action since its protagonist is chained and immobile throughout. At the beginning, Kratos (Authority), Bia (violence), and the smith-god Hephaestus chain the Titan Prometheus to a mountain in the Caucasus, with Hephaestus alone expressing reluctance and pity, and then departing. According to the author, Prometheus is being punished not only for stealing fire, but also for thwarting Zeus's plan to obliterate the human race. This punishment is especially galling since Prometheus was instrumental in Zeus's victory in the Titanomachy.A chorus of Oceanids appear and attempt to comfort Prometheus by conversing with him. Prometheus cryptically tells them that he knows of a potential marriage that would lead to Zeus's downfall. Oceanus, the Titan father of the Oceanids, commiserates with Prometheus and urges him to make peace with Zeus. Prometheus tells the chorus that the gift of fire to mankind was not his only benefaction; in the so-called Catalogue of the Arts (447-506), he reveals that he taught men all the civilizing arts, such as writing, medicine, mathematics, astronomy, metallurgy, architecture, and agriculture.