The tragedy starts on the battlefield in front of the gates of Troy, where the Greeks have taken position. They are interrupted in their siege of the city, because the belligerent women endanger the Greek princes and attack them. The men do not even know who their enemy really is and try to get in contact with the Amazon queen to understand her motives. For the Greek princes the attack is inconvenient, because they are supposed to concentrate on capturing Troy, as Agamemnon, their leader has given order.
In the second scene the Greeks are troubled by the terrible news that Achilles, has been captured by Penthesilea. The messenger gives a vivid picture of the vicious circumstances. The amazons took the Greeks by surprise and surrounded Achilles. First he can free himself and tries to flee. But for bad luck, his horses and his cart collapse and he is put out of action. Penthesilea and her followers draw closer, but when the queen topples and falls, he has another chance to flee, and gets away.
In the fourth scene the Greeks welcome Achilles and acclaim him for his escape. Meanwhile the Amazons rashly celebrate their victory, whereupon Penthesilea gets furious. Her fury culminates in a quarrel with Prothoe, her most intimate confidante and soulmate. The reason is that Prothoe, as the queen later learns, has fallen in love with one of the Greek prisoners of war. At the end of the scene they settle their dispute, because Penthesilea cannot live without the devoted Prothoe.
Now, the Archpriestess gets onto the scene, with her maidens, who are plucking roses for their queen's first victory. Competing for the most and prettiest roses, the girls start to quarrel. Their dispute is interrupted by an Amazon in gear who announces that the Greek prisoners won't accept any hospitality.
The following scene shows an Amazon captain report to the Archpriestess about the fighting between Penthesilea and Achilles. Prothoe tries to convince her leader to return home, but the queen refuses to listen and insists on staying at the place.
This proves to be fatal, because the Greeks start their attack very soon after. Penthesilea refuses to flee, not even on the counseling of her closest confidants and the priestesses with Prothoe declaring to be willing to stay with her and meet their fate.