They wrote and staged their play as an indictment of terrorism, examining the deception and depravity of violent extremists and the people whose lives they ruin.

But now the two women behind the production of “Finist the Brave Falcon” are standing trial in a Moscow courtroom, charged with justifying the kind of acts they meant to condemn.

The director, Yevgenia Berkovich, 39, and the playwright, Svetlana Petriychuk, 44, two highly decorated fixtures of contemporary Russian theater, have been in custody for more than a year. They face up to seven years in prison if convicted.

One of their lawyers and people in the Russian cultural community contend that the prosecution is one of the clearest examples of the accelerating crackdown on freedom of expression since Russia attacked Ukraine in February 2022.

Cultural figures supporting the women say this is the first time in Russia’s post-Soviet era that a work of art is effectively being put on trial. The prosecution has been condemned by some of Russia’s best known intellectuals, including the Nobel Peace Prize laureate Dmitri A. Muratov and the director Kirill Serebrennikov, under whom Ms. Berkovich studied, as well as Amnesty International, Human Rights Watch and other rights groups.

“Finist the Brave Falcon,” interweaves a classic Russian fairy tale with the personal tragedy of a woman who falls in love online with a radical extremist, who deceives her into coming to Syria to join the Islamic State. But there is no happy ending; instead, feeling horrified and betrayed, she returns home to Russia, where she is convicted as a terrorist.

The script was loosely based on the reported experiences of hundreds of women who joined the extremist group from Russia and former Soviet countries like Kazakhstan and Uzbekistan.

As the trial opened last month, both Ms. Berkovich and Ms. Petriychuk said that their play put forth an antiterror message.

“I staged the performance to prevent terrorism,” Ms. Berkovich, said, according to the independent news outlet Mediazona. She said that she felt “nothing but condemnation and disgust” toward terrorists.

“This play is about what not to do,” Ksenia Karpinskaya, a lawyer for Ms. Berkovich, said in a video interview. “It is a prophylactic. You can’t go on stage and say, ‘Don’t join ISIS, it’s bad,’ because no one will go to your play, and no one will listen anyway. But when they show what happened to people who, well, answered this trap of recruiters, everything is clear.”

She called it a “very straightforward play,” and argued that “a play cannot be the object of a crime, because it is a work of fiction.”

But Russian prosecutors have said because the play is about women recruited by the Islamic State, it is justifying, even romanticizing, terrorism.

The case could have a chilling effect on cultural expression, said Mikhail Dyurenkov, a teacher and a former art director of Lyubimovka, the Moscow literary festival where the script of “Finist the Brave Falcon” was given a public reading for the first time, in 2019.

“This opens the door to a world where any person, and any work, can be accused of terrorism, or another crime, just because it was mentioned,” he said.

“Dostoyevsky could have been tried for killing an old woman,” he added, alluding to the plot of “Crime and Punishment,” one of Russia’s most famous novels. The author of “War and Peace,” Leo Tolstoy, “could be tried for inciting a war,” said Mr. Dyurenkov, who fled Russia in the wake of the full-scale invasion of Ukraine.

Even before the verdict, the case is sounding alarms in the Russian theater community, which had been flourishing despite years of creeping pressure on the cultural establishment.

“Of course, it will eventually be destroyed gradually,” said Marina Davydova, a Russian theater critic currently in exile. “Even if it has not yet been destroyed now, it will be destroyed in the near future.”

Before the war, “Finist the Brave Falcon” had little trouble getting to the stage, and initially received the blessing of the state.

The production received financing from multiple state-supported institutions, which means its script was vetted at various stages for potentially offensive content. After it debuted in 2020, it won two Golden Mask awards — Russia’s top honor for theatrical works — a prize supported by official structures, including the Moscow mayor’s office and the Russian culture ministry.

Ms. Davydova pointed out that “Finist the Brave Falcon” debuted years before the criminal trial began; not only did it not violate any rules, she said, but it received broad support and praise from the cultural establishment.

In 2019, before its official debut, it was even performed in a correctional colony for female minors in the Tomsk Region, and a write-up on the institution’s website summarized its message: “The consequences of gullibility and naiveté are terrible — criminal cases and long-term imprisonment.”

“These two young women are being tried for what they did with essentially universal approval,” said Ms. Davydova.

The criminal case was begun several months after a pro-Kremlin actor wrote a post on the social network VK.com expressing disgust that a play directed by an antiwar liberal would be shown in his city, Nizhny Novgorod, in the wake of Ukraine’s attack on the Crimean Bridge earlier that month. He labeled the show “undisguised sympathy for Ukraine and hatred of the current government.”

The performance there was canceled and the man, Vladimir Karpuk, eventually became one of the star witnesses for the prosecution.

Another key prosecution witness was a religious studies professor at Moscow State Linguistic University, Roman Silantyev, who produced an analysis that found that the text “сontains signs of the ideology of Islamism and jihadism, as well as radical feminism and the fight against the androcentric social structure of Russia.”

Mr. Silantyev is known as the founder of a controversial discipline called “destructology” that has been dismissed by leading Russian experts as “pseudoscience.”

After a lawyer for the defense asked the Russian Ministry of Justice to review Mr. Silantyev’s analysis of the play, the ministry stated that his statement could not be considered expert testimony, because “destructology” cannot be considered a scientific discipline.

But another expert was assigned from the Federal Security Service, or F.S.B., who found that the play “romanticized the image of terrorism.”

Another witness is a person who has not been identified publicly and has been testifying from an undisclosed location; the witness’s face has been hidden and the voice disguised. Reports from the trial by independent Russian media outlets indicate that the person has been unable to answer basic questions about the play and its performances.

Once the prosecution finished presenting its evidence earlier this month, it asked that the trial be closed to the public, which the judge agreed to.

Ms. Berkovich, the director, comes from a family of advocates — her mother is a human-rights activist, as was her grandmother, and her father is a poet. On the first day of Russia’s full-scale invasion, Ms. Berkovich was arrested and jailed for 11 days after holding a poster with the inscription “No to War,” and allegedly disobeying the police officers who demanded she accompany them to the station. She has also written antiwar poetry.

The playwright, Ms. Petriychuk, became well-known in the Moscow theater world in 2018, when she had her first reading at the Lyubimovka theater festival and began winning recognition and awards.

Both women have repeatedly asked that their detention be changed to house arrest. Ms. Petriychuk has scoliosis, a curvature of the spine, and Ms. Berkovich is mother to two adopted teenage daughters. She met them at a summer camp for orphans, where she and some friends were helping young campers put on plays for potential adoptive families.

“It’s awful, it’s very hard for them,” Ksenia Sorokina, a friend of Ms. Berkovich, said of the two daughters. “This is a terrible trigger for them, to repeatedly lose their parents.”

In April, just before the trial began, both women were added to Russia’s official list of “terrorists and extremists,” freezing their bank accounts. The list includes the Islamic State, Al Qaeda, the Taliban, political opposition figures such as the late Aleksei A. Navalny, the “international L.G.B.T movement” and Facebook’s parent company, Meta.

Mr. Dyurenkov, the former art director of the Moscow festival, said he expected more prosecutions of this kind. “Once this door opens, it doesn’t close anymore,” he said. “This is how the repressive system works.”