Jason calls Medea the most detestable creature of all time. She has killed his children and destroyed him. He curses her. He says he is sane, but was mad to bring her from a savage land to Greece. He recounts how Medea killed her own brother to join him and says that no Greek woman could have killed her own children. He calls her a lioness, not a human. He calls her a vile creature, a child-murder, and commands her to get out of his sight.
Jason reveals that Medea was correct about what she could do to most hurt him—she has bereft him of the potential for future children and robbed him of the children he already had. Jason attributes Medea's seemingly unnatural actions to her being a foreigner, a non-Greek. Her inhumane behavior, in his eyes, has robbed her of her human form. Jason, it seems, is a human (capable of feeling grief and pain) after all.
Medea says she would respond at greater length, but Zeus knows what she did for Jason and how he dishonored her. He can call her a lioness if he likes, but she sees through him. He says she suffers too for her actions, but she says being spared his mockery relieves her. Jason calls out to his dead children saying what an evil mother they had. Medea says it was their father's sickness that killed them. Jason asks if this matter of sex was enough for Medea to kill them, and she asks if he thinks that is no small matter for a woman.
Even the death of their children cannot provide Jason and Medea with a respite from their arguments and mutual hostility, their fundamental disagreement about who was the ultimate cause of their children's death. Note that Medea acknowledge that she does feel grief and pain after the murders. She also confirms Jason's argument that she was motivated out of sexual jealousy, but where he (the betrayer) sees this as a minor thing she (the one betrayed, and who sees herself as representing all betrayed women) sees it as a very big deal indeed, suggesting that it is a symptom of the repression and submissiveness forced upon all women.
Jason says his infidelity would be a small matter to a sensible woman, but to Medea everything is disaster. Medea says that the gods know who caused this calamity. Jason retorts that they know her "abominable mind." Jason asks for his sons' bodies to bury and mourn. Medea refuses, saying she willy bury them herself at a sanctuary to the goddess Hera. She will establish a solemn festival in Corinth to atone for the killing of her children. She will go to Aegeus in Athens, and she prophesizes that Jason will die ignobly, struck on the head by a piece of his old ship, the Argo.
Once again Medea's travails are attributed to her excessive emotion and passionate nature. It seems, based on how things have gone according to Medea's plan and Helios' decision to send Medea a flying chariot, that the gods do indeed agree with Medea that Jason was the author of the calamity (the cause of the tragedy). Medea acknowledges that her actions were severe enough to require atonement in the form of a solemn festival. Jason will symbolically meet his end by being killed by a piece of the ship that carried him on his quest for the Golden Fleece and, in so doing, brought him to meet Medea.
Jason calls on avenging Furies and bloody Justice to destroy Medea. Medea asks what gods could listen to a man who breaks his oaths. They exchange biting insults. Medea tells Jason to wait until he is old to mourn—it is too early now. Jason says he longs to kiss his children again. Medea notes the irony of his wanting to touch and talk to them now when before he had banished them. He begs her. She says he is wasting breath.
Medea once again calls attention to Jason's hypocrisy when he calls on Justice to come to his aid when he has behaved unjustly all along. We see that Jason, now that he can no longer touch them, longs for his sons—a condition of desire recognizable as fundamentally human and so flawed. Medea, meanwhile, delights in taking vengeance on the man who betrayed her.
Jason calls on Zeus to witness how Medea, a child-murderer, is driving him away. He swears that he will call on the gods to witness her vile deeds as long as he has strength. He wishes he had never had children only to see her murder them.
Now that Jason is wronged, he calls on Zeus to witness the fact. Yet he did not call on Zeus when he wronged Medea, nor was he willing to admit that he had even wronged her by abandoning her and not resisting when she was sentenced to exile.
The Chorus speaks the final words in the play, saying that Zeus ordains many fates and the gods bring many things to end unexpectedly. What seems likely doesn't happen and unlikely things come to pass instead. So, the Chorus says, ends this story.
It is notable that the Chorus suggests that the conclusion of the events in the play is unexpected when they have been known, built, and foreshadowed throughout the course of the play. Perhaps what the Chorus means is that child-murder is so reprehensible and egregious that it always seems unexpected, or perhaps what is unexpected is that the gods seem to agree with Medea, to see the child-murder as a necessary aspect of the punishment of Jason for his injustice toward Medea.