At a feast in honour of the god Apollo, Adrastus suggests that the two exiles marry his young daughters. He also explains that the feast commemorates a legend from his city's history: Psamathe, daughter of the Argive king Crotopus, is raped by Apollo and gives birth to his son Linus. After Linus is killed by a pack of dogs, the princess confesses her plight to her father who punishes her by death. A child-eating monster, summoned by Apollo, is sent to Argos but killed by a youth named Coroebus. The young man offers to sacrifice himself to appease the god's wrath. Apollo, however, is so moved by this offer, that he decides to spare both Coroebus and his city.