Frogs, or The Frogs, is one of Aristophanes's greatest comedies and is justly celebrated for its wit and keen commentary on Athenian politics and society. It is the last surviving work of Old Comedy and is thus also notable for heralding a passing era of literature. While it is a comedy, it is also a trenchant political satire and expresses Aristophanes's views on Athenian democracy, the value of poetry The play begins with Dionysus, dressed up as Heracles, and his servant Xanthias, riding a donkey, traveling to Heracles' house. Heracles is amused at Dionysus's costume. Dionysus asks him how they can get to the underworld to fetch the poet Euripides for Athens, and what sort of obstacles they might expect to encounter. Heracles provides them with information, and the travelers depart.
Dionysus is ferried across the lake by Charon, but Xanthias has to travel around because he is a slave. Along this journey, a chorus of frogs bursts out into song, annoying Dionysus. However, the god then joins in their boisterous song.
Dionysus and Xanthias join up on the other side of the lake, but before they can go very far they encounter the monster Empusa. Dionysus is extremely frightened and soils his clothing. The Chorus of Initiates, part of the Eleusinian Mysteries, enters and sings a song to Iacchus, Demeter, and her daughter Persephone.
Arriving at Pluto's house, Dionysus and Xanthias knock on the door. Thinking he is Heracles, the doorman, Aeacus, curses him. Dionysus tells Xanthias to wear his disguise, but asks for it back once a beautiful woman comes outside and invites "Heracles" to a banquet with other ladies. The innkeeper and Plathane come out and lambast the supposed Heracles as well, prompting Dionysus to once more give the costume back to Xanthias.
Aeacus returns and orders the seizure of Heracles for past his bad deeds. Xanthias-as-Heracles says Aeacus ought to torture his slave (Dionysus) to prove his own innocence. Eventually both claim to be gods, and Aeacus tortures both to see if this is true. Both Xanthias and Dionysus feel pain but pretend not to, as gods normally are not supposed to feel bodily pain. Finally, Aeacus says he will see if Pluto and Persephone will vouch for their divinity.
Inside, Aeacus talks to Xanthias about how Aeschylus and Euripides are fighting over who is the most accomplished tragic poet. Aeschylus already possesses the chair but Euripides is challenging him for it. Pluto calls a contest and Dionysus is made the judge. Both poets criticize each other, and then pray to their respective gods. The competition begins.
In a series of contests, Aeschylus and Euripides discuss who is better at prologues, lyrics, and making their audience better citizens. Euripides claims to have slimmed tragedy down from its ponderousness and made it more accessible to the common person. He also says Aeschylus is verbose. Aeschylus, for his part, criticizes the meter of Euripides' work and claims that his verse is wanton.
Dionysus cannot seem to come to a conclusion, so he orders the two poets' verses to be weighed. Because he refers to lofty things such as death and rivers, Aeschylus wins the weighing.
Finally, the two poets are asked to comment on how the Athenians should deal with the statesman Alcibiades. Dionysus decides Aeschylus is the overall winner, and he, the poet, and Pluto return to Pluto's house for a banquet. Aeschylus tells Pluto to give his chair to Socrates once he departs for the upper world. The chorus praises Aeschylus and proclaims that it hopes he will assist Athens with sound advice.