At an army encampment in the port city of Aulis, Greece, Agamemnon—the king of Mycenae and the leader of the Greek expedition against Troy—paces nervously outside his tent in the hours before dawn. The winds in Aulis have ceased, so the army’s ships are stalled in the harbor. Agamemnon calls for his attendant, an old man who is the longtime servant of Agamemnon’s wife, Clytemnestra (who is home in Mycenae with their many children). The old man notices Agamemnon’s agitated demeanor and asks what’s wrong. Agamemnon reveals that he’s learned some terrible information: the only way to get the winds moving again, according to the prophet Kalchas, is for Agamemnon to sacrifice his eldest daughter Iphigeneia to the goddess Artemis. The sacrifice will be retribution for Agamemnon angering Artemis by killing a deer, an animal sacred to the goddess, on his way to the port. Upon learning the goddess’s demands, Agamemnon begged his brother Menelaos—who has called up the armies to sail on Troy in order to reclaim his wife, Helen, from her elopement with the Trojan prince Paris—to call off the troops, but Menelaos refused. Agamemnon sent a letter home to Mycenae calling Iphigeneia to Aulis under false pretenses: he told her she is to be married to the great warrior Achilles. Agamemnon, however, wants to make things right and prevent Iphigeneia from meeting a terrible fate. He asks the old man to hurry off and deliver a new letter to Mycenae which begs Iphigeneia to stay away from Aulis at all costs. The old man, though appalled by the king’s actions, agrees to deliver the letter and hurries away. Agamemnon, exhausted, retreats into his tent. A chorus of young Chalkidian women comes forward to comment upon the action. The women praise the might of the Greek army, the handsomeness of its soldiers, and the swiftness of its ships as they pray for a successful campaign against Troy.
Menelaos enters, dragging the old man with him—he has intercepted the old man on his way to deliver Agamemnon’s letter. Agamemnon comes out of his tent and Menelaos accuses him of trying to betray the Greek cause—he reminds Agamemnon that he was keen to lead the armies for Troy until he received word that he’d have to sacrifice something of his own to get them there. Agamemnon in turn accuses Menelaos of putting his own family—and all of Greece—in jeopardy all for the sake of retrieving his unvirtuous wife. As the men argue back and forth, a messenger arrives to tell Agamemnon that Clytemnestra has arrived with their infant son Orestes and Iphigeneia in tow. Agamemnon solemnly laments to Menelaos that he has “fallen into the snare of fate” and that he has no idea of what to do. Menelaos, overcome with empathy, tells Agamemnon that he has been right all along—Iphigeneia must be spared. Agamemnon thanks Menelaos for his change of heart but he admits that he fears it’s too late—if the men realize that Agamemnon has betrayed their cause, they will turn on him and kill him, his wife, and his children anyway. Menelaos somberly departs. The chorus laments the terrible decision Agamemnon must make.
As a chorus of attendants helps Clytemnestra, Iphigeneia, and Orestes from their chariot, Clytemnestra fawns over her children and expresses her excitement for Iphigeneia’s wedding day. Iphigeneia is bursting with excitement to see Agamemnon, whom she loves dearly. As Agamemnon steps out of his tent to greet his family, however, Iphigeneia notes his distracted demeanor. Agamemnon blames his mood on the impending war but he can barely hold himself together in the face of his favorite daughter. He begins crying about how much he’ll miss Iphigeneia, who assumes he is referring to her impending marriage. She comforts him blithely, then heads inside the tent. Clytemnestra, too, tries to comfort her husband by assuring him she feels the same parental grief over sending their eldest child off to be married. As Clytemnestra excitedly asks about wedding preparations, Agamemnon tries to tell her that she should let him handle the ceremony and return home with Orestes. Clytemnestra refuses. Miffed, she heads into the tent. Alone again, Agamemnon laments his position, then goes off to meet with Kalchas to make final preparations for the sacrifice of Iphigeneia.
Achilles enters, demanding to see Agamemnon—he and his troops are frustrated by the long wait in Aulis and the silence from their leadership. Clytemnestra exits the tent and exuberantly introduces herself to Achilles, excitedly telling him that their families are soon to be joined through marriage. Achilles, who has no idea that his name has been used as part of Agamemnon’s plot to draw Iphigeneia to Aulis, is not just confused but actively disgusted. Clytemnestra, humiliated, apologizes. The old man, having overheard their conversation, comes out from the tent and explains everything to both of them, revealing Agamemnon’s plans for Iphigeneia’s sacrifice and his deception of both Achilles and Clytemnestra as a means to that dreadful end. As Clytemnestra receives the news of Agamemnon’s plan, she falls to her knees and begs Achilles to save her and her daughter. Achilles agrees to help Clytemnestra. He promises that he will not let Iphigeneia come to harm—he will defend her until his last breath as if she truly were his bride. He suggests the innocent girl be kept ignorant about the terrible fate her father has planned for her. In the meantime, Achilles suggests, Clytemnestra should go to Agamemnon and attempt to reason with him herself. Achilles promises that if she fails to move Agamemnon’s heart, he will then intervene on her behalf. While Clytemnestra goes back inside to wait for Agamemnon’s return, the chorus of Chalkidian women laments that the men in charge of leading the Greek armies to Troy have “put justice behind them.”
After the chorus’s lament is finished, Clytemnestra emerges from the tent to declare that Agamemnon is nowhere to be found. Frustrated, Clytemnestra has told Iphigeneia of her father’s plans. Agamemnon enters and asks for Iphigeneia to be brought forth to be married—he is still keeping up with his ruse. Clytemnestra decides to play along and calls Iphigeneia out from the tent. Iphigeneia, with Orestes in her arms, emerges from the tent shielding her face. Once Iphigeneia is present, Clytemnestra demands Agamemnon tell the truth. When he plays dumb she rails against him, reminding him of all the loyalty she’s shown him over the years. She threatens to turn against him forever if he hurts Iphigeneia. The chorus urges Agamemnon to heed his wife. Iphigeneia steps forward and begs her father to spare her—she is innocent, she says, and she has nothing to do with the strife Helen and Paris have wrought. Agamemnon, however, laments that he has no choice in the matter—the Trojan war is the will of the gods themselves, and if he is the one to prevent it from happening he’ll surely incur even more of their wrath. Agamemnon solemnly walks away. Iphigeneia curses her father, her country, and her fate. Achilles enters; behind him, the angry screams of a mob of men can be heard. Achilles warns Iphigeneia that more and more men are calling for her sacrifice—they are increasingly impatient to get sailing. Achilles vows to protect Iphigeneia against every last one of them, even if his own troops should turn against him. Iphigeneia, however, steps forward and declares that there’s no use in fighting or “hold[ing] out against the inevitable.” She has decided to sacrifice herself in hopes that her name and her country will both come to glory. Achilles begs Iphigeneia to flee Aulis with him and come home to be his bride, but Iphigeneia’s mind is made up—she is ready to die so that Greece can be free. She begs her mother not to cry or to be angry with Agamemnon. After bidding her mother and younger brother goodbye, Iphigeneia sings a plaintive yet joyous lament to the goddess Artemis, hoping that her blood will appease the goddess and bring success to the Grecian campaign. Iphigeneia walks away toward the sacrificial altar, where her father and Achilles are waiting for her. Clytemnestra takes Orestes back into the tent.
Sometime later, a messenger arrives with joyous news: a miracle has occurred at the altar. Clytemnestra exits her tent to hear the messenger’s tale. The messenger reports that as the prophet Kalchas prepared to bring the knife down on Iphigeneia’s throat, the girl transformed into a deer, signaling Artemis’s satisfaction with the sacrifice. Iphigeneia has been spared, the messenger reports, and brought up to heaven to live among the gods and goddesses. The winds have picked up, and the men are about to sail for Greece; all is well. Agamemnon approaches and bids Clytemnestra goodbye. He begs her not to be angry with him. She does not respond but instead she turns quietly and enters the tent as Agamemnon triumphantly leads his men down to the harbor where their ships await them.
