Karina Gauvin (Niobe); Philippe Jaroussky (Anfione); Amanda Forsythe (Manto); Christian Immler (Tiresia); Aaron Sheehan (Clearte); Terry Wey (Creonte); Jesse Blumberg (Poliferno); José Lemos (Nerea)
Steffani's opera has three acts, and as things get underway, Anfione, the King of Thebes, decides to retire. He'll summon a loyal associate, Clearte, to serve as Regent. But naturally, there's a complication -- Clearte is secretly in love with Niobe, and thinks it best to avoid her company.
Meanwhile, in an ongoing subplot, the young woman Manto is attacked by a marauding bear. She's rescued by the prince Tiberino, and introduces her new hero to her father Tiresia, a blind High Priest with clairvoyant powers.
We next meet the sworn enemy of Thebes, Prince Creonte of Thessaly. Before long, he's also in love with Niobe -- thanks to a spell cast on him by the devious sorcerer Poliferno.
In Thebes, the retired King Anfione devotes his time to his studies, concentrating on the harmony of the spheres. But news arrives that Creonte's army is launching an attack. That prompts Anfione to stop studying for a while, and try to save his city. In a trancelike prayer, he appeals to the god Jove. And magically, walls spring up from the earth and surround Thebes, preventing Creonte's advance.
At that, Niobe declares her husband a god. This offends the high priest Tiresias, whose objections in turn anger Niobe. She throws him to the ground and demands that he bow to Anfione.
Manto comes to his assistance, along with Tiberino. They help him up, and send him off to safety with Tiberino's men. As the act ends, Manto and Tiberino have some time to themselves, and Tiberino decides to declare his love.
In ACT TWO, we find that Poliferno and Creonte managed to sneak into Thebes before the city's magical new walls sprung up. Now, Poliferno has made them both invisible, so they can spy on Niobe. As they watch, Niobe takes advantage of Clearte's feelings for her, and persuades him to take the throne.
This takes Anfione by surprise. In all the excitement, he apparently forgot his decision to retire as king. He's briefly angry, but calms down when Niobe presents him with a starry shrine, where he can enjoy his new, godly status.
Poliferno then launches another spell, and in a flash he has abducted Niobe. He takes her deep into the forest, and tells her the god Mars has chosen her to be his wife. She believes it, and she and "Mars" are quickly in a passionate embrace. But it's all part of Poliferno's magic. The supposed god that Niobe has fallen for is actually Creonte, in disguise.
Back in Thebes, the High Priest Tiresias has figured it all out. He tells Anfione exactly what happened, and the king vows to get Niobe back and take revenge.
The act then ends with another look at the romance between Manto and Tiberino. As always, the young lovers are cynically observed by the wisecracking nurse, Nerea.
As ACT THREE begins, Niobe is still making whoopee with Creonte in his Mars disguise. But Poliferno interrupts their fun by announcing that Anfione is on the way with his army to reclaim Niobe. Creonte chooses safety over romance, and takes off with Poliferno. When Anfione arrives, he tells Niobe that she's been tricked. Niobe blames the whole mess on the gods, and boldly decides to get even with them.
The next scene is at the Temple of Latona -- mother of the gods Apollo and Diana. The lovers Manto and Tiberino have finally resolved their romantic struggles, and are married by Manto's father, the High Priest Tiresias.
But everything comes to a halt when Niobe arrives in a fury. She declares herself superior to the gods, and destroys the temple altars. She then announces that she and all 12 of her children are now gods themselves.
In Thebes, Niobe leads her children, the Niobids, in a triumphant procession. It's all too much for the real gods. Apollo and Diana descend from above, demolish the city walls and kill Niobe's children with flashing arrows and bolts of lightning. King Anfione has watched it all. Remorseful, he stabs himself, then dies just as Niobe reaches his side. Niobe's grief is so overwhelming that she can't even summon a tear, and turns to stone.
With that, Creonte is free to enter the city in triumph. With his victory seemingly blessed by the gods, he banishes the sorcerer Poliferno. Then he blesses the marriage of Manto and Tiberino, and there's a great celebration as the opera ends.