Thyestes enters with his sons. He reflects on how much he has missed Argos and of the joy of being welcomed back from exile, but cannot help but feel fearful and suspicious. Thyestes’s son, named Tantalus like his great-grandfather (hence “Tantalus Junior”), asks his father why he hesitates. Thyestes admits that he is not sure why he is afraid, though he cannot shake the feeling that he is better off without the ever-present anxiety of power. Nor does Thyestes trust Atreus, knowing how much he hates him. Still, Thyestes agrees to put aside his misgivings because this is what Tantalus or Thyestes Junior wants.

Atreus, watching, delivers a soliloquy in which he observes that Thyestes has fallen into his trap, but he must contain himself for a little longer. He welcomes Thyestes with feigned joy. Thyestes begs forgiveness for the terrible things he has done to Atreus, and Atreus eagerly speaks of returning his “father’s crown” (528) to his brother. He promises that the two of them will share the kingdom of Argos from now on.

The Chorus sings the third ode. They can hardly believe the change that has evidently come over Atreus, evidence, as they see it, that “true devotion” (549) and “true love” (551) always put an end to even the most vicious of rivalries.