Melanie Diener (Isabella); Morten Frank Larsen (Friedrich); Sonja Freitag (Dorella); Anna Gabler (Mariana); Bernhard Berchtold (Luzio); Benjamin Bruns (Claudio); Maximilian Argmann (Antonio); Julian Prégardien (Pontio)
As ACT ONE begins, the king of Palermo is absent, and has left the city in the control of Friederich, a German viceroy. Friederich is a bit puritanical -- to put it mildly. So among the first things he does is to forbid any public -- or even private -- displays of pleasure and affection. So he won't be tempted himself, he actually sends his own wife, Mariana, away to a convent. He has also cancelled the upcoming carnival, and the penalty for violating Friederich's new rules is death.
Among the victims of Friederich's ban on pleasure are the young nobleman Claudio, the innkeeper Danieli, and the inn's barmaid Dorella. All three have been arrested by Brighella, Friederich's enforcer, and are awaiting punishment. But Claudio isn't going down without a fight. It seems that Claudio's sister Isabella is in the same convent where Friederich's wife was sent. So Claudio enlists his friend Luzio to visit the convent, and convince Isabella to appeal to Friederich for clemency.
Luzio visits the convent, where he makes his plea to Isabella. He's struck by her beauty, and begins to fall in love. But Isabella can only think of her brother, and ponders how she might win his release.
In the city, Brighella and Friederich are busy laying down the law. Brighella exiles one man, Pontio, for abetting prostitution. But when Dorella is brought for sentencing, Brighella finds her attractive, and sparks begin to fly. That's nipped in the bud when Friederich appears. He tears up a petition from the people to reinstate the carnival. And he sentences Claudio to death.
That's when Isabella turns up from the convent and goes into action to save her brother. First, she demands a private audience with Friederich. He grants it -- and promptly reveals his own hypocrisy. He tells her that he might just release Claudio, but only if she agrees to meet him in secret -- and spend the night with him.
At first, Isabella is appalled. Then she comes up with a plan. She might be able to send Friederich's wife Mariana to the secret meeting in her place, and catch him red handed. So with that in mind, she agrees to his conditions. But nobody else knows what Isabella is up to. So as the first act ends everyone is astonished that Isabella seems to be cooperating with the evil Friederich
ACT TWO begins with Isabella visiting Claudio in prison. She's trying to keep her plan a secret, so she tells him she's willing to give up her honor to save him. At first, he's appalled. But when he considers the prospect of his own execution, he changes his mind and urges her to go through with it.
So Isabella sets things in motion. She'll invite all concerned to attend a masked ball. She gives her friend Dorella a letter, to be delivered to Friederich. She also visits Claudio's friend Luzio, telling him Claudio is about to be freed, and summoning him to the ball, as well – and it’s obvious the two of them have eyes for each other.
Friederich, for his part, has no intention of fulfilling all of his deal. Sure, he'll spend the night with Isabella. But he has no plans to call off Claudio's execution. When Isabella's letter arrives, Friederich puts on a mask and sets off for the ball -- ignoring the fact that it's just the sort of revelry he himself has forbidden. But when he approaches the woman he assumes is Isabella, she springs her trap. Friederich is seen to be romancing his own wife, Mariana, while thinking she was someone else.
To his credit, Friederich admits his guilt -- and offers to be punished according to his own laws. But the people are in a festive mood, and let him off the hook. Friederich is reconciled with Mariana. Claudio goes free. And for good measure, Isabella gets together with Luzio, and Dorella gets the man she wants, the enforcer Brighella. Then the King of Palermo finally returns. Friederich's rule of the city is over, and everyone is happy as the opera ends.