Philocrates and his slave Tyndarus, of the Greek district of Elis, have been captured in war with another Greek region, Aetolia. They are now prisoners and slaves bought by Hegio, a well-to-do resident of Aetolia, who is planning to trade them for his son, Philipolemus, who has been captured in Elis. Pretending to be each other, the supposed slave Philocrates is sent to make the trade, while Tyndarus risks his life by remaining. A friend of Philocrates named Aristophontes has also been captured, and Tyndarus’ efforts to fool Hegio by claiming that Aristophontes is insane are unsuccessful. When Hegio finds out from Aristophontes that he has been deceived, he sends Tyndarus to the quarries for backbreaking labor. Declaring that dying courageously is not an everlasting death, Tyndarus tries to convince Hegio that his own loyalty to Philocrates is right. Comic relief is provided by a sponger, Ergasilus, looking for a free dinner from Hegio. He has learned that Hegio's son Philopolemus has returned to Aetolia, and he uses this knowledge to get a free meal from Hegio, then proceeds to go wild in the kitchen. Hegio’s former slave Stalagmus, who stole Hegio's other son when he was four years old, also arrives on the scene and confesses his iniquity. Eventually everybody discovers that Tyndarus is that stolen son, causing Hegio to realize he should have treated him better when he was his captive slave. Hegio and his two sons, Philopolemus and Tyndarus, are reunited in a happy ending. [Source: wiki]