Playwright Matthew Libby wrote "Sisters" about a girl and her AI sibling, and then the real world caught up with his script. The play runs at Writers Theatre's Gillian Theatre in Glencoe through Nov. 8.

In a Q&A published in April with Writers Theatre dramaturg Bobby Kennedy, Libby said real-world AI had already outpaced the technology in his play. "Right now you could ask for an AI companion like Greta and it would immediately come out," Libby said. "There wouldn't be any adjustment period of talk more human; it would come out fully formed."

He said he now thinks less about the play's setup and more about its vision of the future. In the Q&A, he asked: in a world increasingly saturated by technology, how do people hold on to love and decency and kindness?

"Sisters" tells the story of Matilda, a human who ages from childhood to old age on stage, and Greta, an AI sister who exists only as a voice from a device. Brenda Barrie plays Matilda. Chloe Johnston plays Greta, heard but never seen. Both actors are making their Writers Theatre debuts.

Writers Theatre released Episode 21 of its Green Room podcast on Sunday, Oct. 11, featuring Libby discussing how audience responses to "Sisters" have evolved as AI becomes a bigger part of daily life. The world premiere took place roughly two years before the Glencoe production, and Libby told Kennedy in April that the conversation around the play has shifted in that time.

Libby studied cognitive science and creative writing at Stanford University and holds an MFA from New York University. His Off-Broadway play "Data" received an Outer Critics Circle nomination for the John Gassner Award earlier in 2026.

The production is directed by Jessica Thebus, who directs Northwestern University's MFA Program in Directing and previously directed "The Turn of the Screw" at Writers Theatre. The set, described by the Chicago Reader as "simple, stark," keeps all technology off stage. Libby has said that choice is deliberate: the play is not about how the AI works but about what it means for the humans around it.

Libby drew personal inspiration from his grandfather, Paul Libby, an aerospace engineer who helped found UC San Diego's engineering department in the 1960s. When Paul Libby turned 100, he began experiencing dementia. That experience shaped the play's treatment of memory loss.

"Sisters" follows last season's sold-out run of "JOB" at Writers Theatre. The theater staged Jordan Harrison's "Marjorie Prime" in 2015, another play exploring AI and dementia, as the final production in its original Books on Vernon venue.

Tickets run $81–$86.

Seating is general admission, and late seating is not permitted. A closing-day "Final Word" audience discussion takes place Sunday, Nov. 8, at noon. Writers Theatre also offers a Childcare Matinee for parents: children ages 5–11 can attend an on-site theater class during a Sunday performance for $10 (subscribers) or $15 (single ticket holders). The Gillian Theatre is at 325 Tudor Court, Glencoe. The box office number is 847-242-6000.