The play begins with two gods, Athena and Poseidon, descending from the heavens to discuss the aftermath of the war between the invading Greek armies and the people of the city of Troy. Poseidon has supported the Trojans, whereas Athena has supported the Greeks. However, she has now turned against them. The Greek warrior, Ajax, raped the Trojan princess Cassandra in Athena’s temple, which the goddess sees as an act of great disrespect. As a result, she has called on Poseidon, as well as Zeus, to work with her to create stormy seas to punish the Greeks on their journey home.
The gods exit, and the mortal plot unfolds. The stage shows a ruined wall, and in front of it a tent containing the recently enslaved women of Troy. Hecuba, the former queen of Troy, laments the destruction of her city, and the horrible treatment her family has endured. The Chorus, made up of her former handmaidens and other noble Trojan women, joins her, and together they sing, wondering what will become of them and which Greeks will be their masters.
Talthybius, a Greek guard, enters and tries to inform Hecuba of the death of her daughter, Polyxena. He uses euphemistic language, and Hecuba does not initially understand what he is trying to say. He also announces to the women that they will all be taken as slaves by different Greek men, and so will have to leave their homeland essentially alone.
Cassandra, Hecuba’s daughter, who was cursed with the ability to see the future, enters the stage from the tent. She is in a wild, panicked mood — she has seen that Agamemnon will enslave her, and that her enslavement will lead to her death and the death of his entire family. She talks of Agamemnon as her husband, and likens her enslavement to marriage. Because she can see the future, she knows that she cannot fight it, and leaves willingly for Agamemnon’s ship.
Next, Andromache, Hecuba’s daughter-in-law and husband of the late warrior Hector, enters carrying her baby Astyanax. She and Hecuba sing a song of mourning together. Andromache reveals that Greek soldiers killed Polyxena. She tries to comfort Hecuba by arguing that it is better to be dead than to be alive and suffering.
Andromache is taken away to the ship of her new master, but before she goes Talthybius informs her that she cannot take her baby. A panel of Greek warriors has decided Astyanax must die, because if he were to live and grow into a man he could pose a potential threat to his Greek captors. Devastated, Andromache gives Astyanax to Talthybius, and the two exit the stage.
Menelaus, the Spartan king, comes to claim Helen. Helen was formerly his wife, but she eloped with the Trojan prince, Paris. Menelaus rallied his allies and came after her, thus starting the Trojan War. Menelaus now plans to transport Helen back to Sparta and kill her, as a warning to all unfaithful wives, but first she tries to plead her case. Hecuba, who has been listening, argues that Helen is twisting the truth. While Helen says she was taken to Troy and kept there against her will, Hecuba argues she eloped willingly and is to blame for the destruction of the city. Menelaus is not convinced by Helen, and the two leave together, she as his slave.
In the play’s final scene, Talthybius returns with the body of Astyanax. He allows Hecuba to dress him and perform funeral rites, and gives her Hector’s shield, which will serve as a coffin for the child. Hecuba laments this loss of young life, and reflects upon the destruction of her city and her loved ones. The Greek ships begin to leave, and as they leave the remaining Greek soldiers set Troy on fire. As their home burns, the Trojan women sing a sad song together, and prepare for their new lives.