Callidorus, the young son of the Athenian nobleman, Simo, laments to his slave Pseudolus, a clever fellow, about how his love, Phoenicium, has just been sold to a Macedonian general by her pimp, Ballio, for 2500 drachmae, 500 of which is to be delivered that day by messenger.
Pseudolus then instructs this slave to retrieve the 500 drachmae and the letter from the Macedonian General from the messenger while he is asleep and to impersonate Harpax while meeting with Ballio.
Pseudolus is an example of the stock character of the clever slave, common in Plautus' works.
Scenes 1-2: Young Calidorus explains to Pseudolus, his family's slave, that his girlfriend Phoenicium has been sold to a Macedonian soldier by Ballio, the double-crossing leno ("pimp") who owns her and had earlier promised to sell her to no one but Calidorus.
Pseudolus approaches them and warns Simo that he plans to get 20 minae from him by the end of the day.
Pseudolus pretends to be Ballio's assistant and manages to steal the letter from Harpax without his noticing; he then sends him away to take a nap in an inn, promising to fetch him as soon as Ballio comes home.