SPOILER ALERT: Do not read if you have not yet watched “Red vs. Blue,” Monday’s episode of “9-1-1: Lone Star.”

Lisa Edelstein is exiting “9-1-1: Lone Star” after playing Gwyneth Morgan, the ex-wife of Rob Lowe’s Chief Owen Strand and the mother of Ronen Rubinstein’s T.K. Strand, for two seasons on the Fox drama, Variety has learned exclusively.

Edelstein’s departure was hinted at in the final moments of Monday’s episode of “Lone Star,” when T.K. received a devastating phone call letting him know that his mother had been killed. However, this hour, “Red vs. Blue,” did not actually show Gwyn’s death, and “Lone Star” fans will get a chance to see her again before she’s officially gone.

Variety can confirm Edelstein’s farewell will come on next week’s “9-1-1: Lone Star,” an episode that is sure to be a tearjerker for viewers at home — and T.K. and Owen on screen.

Here’s the official description for that episode, titled “In the Unlikely Event of an Emergency”: When Gwyn has an emergency, Owen and T.K. travel to New York, but the plane experiences a mechanical failure. T.K. reflects back when Gwyn helped get him into rehab years ago.

“Life is never one thing. And it’s relentless. I wanted Gwyn’s death to happen the way these sometimes do — out of the blue and without fanfare,” showrunner Tim Minear told Variety. “It comes at a moment for TK when things are good. He and Carlos are at the next level. His fire family has been reunited. His mother’s death is a game changer for TK. But also for Owen and Carlos. The way TK deals with this loss and grief will tell us a lot about where he is and where he came from. And Owen will have his own reckoning with his past with Gwyn.”

Edelstein is best known for her role as Lisa Cuddy on Fox’s “House,” as well as her parts on Bravo’s “Girlfriends’ Guide to Divorce,” NBC’s “The West Wing” (which she starred on alongside Lowe) and Netflix’s “The Kominsky Method,” among many others. She made her debut on “Lone Star” in the Season 2 premiere in January 2021. Edelstein had the recurring role of Gwyn — who had an on-and-off relationship with her ex Owen and a strong bond with their son T.K. — throughout the show’s second season, and was featured in seven of the season’s 14 episodes. In the currently airing third season, she has appeared in two out of the first seven episodes, with the upcoming eighth marking her final episode.

At the time of her death, Gwyn was in New York City raising her infant son Jonah with his father, her ex-boyfriend Enzo. Gwyn and Owen had originally thought the baby was his, conceived when they rekindled their relationship during the COVID-19 lockdown in Austin.

See the promo for next week’s “9-1-1: Lone Star” below.