Is 9-1-1 's Hen really leaving the 118? Watch a tense preview clip: 'You're not a firefighter anymore'

Hen's decision to leave her job as a firefighter paramedic to continue medical school is proving to have dire consequences right off the bat.

In the final moments of last week's episode of 9-1-1, viewers saw Karen (Tracie Thoms) calling in a deadly explosion at her office. Tonight's episode, "Tomorrow", sees Hen (Aisha Hinds) rushing to the scene. Her son Denny (Declan Pratt) is safe and sound, but Karen is still in the building, and Bobby (Peter Krause) won't let her suit up and join her former 118 colleagues for the rescue.

"Hen, no, you're not going inside," Bobby tells her in a preview clip exclusive to EW. "You are not a firefighter anymore and you're too close to the situation. I love you, now let us do our jobs."

"Bring her back to me, Cap," Hen tells her former captain.

Hinds spoke to EW earlier this season about how much Karen means to Hen, saying she is "her grounding force, and her conscience, and her mirror." The actor also discussed how pursuing a career as a doctor would test her like never before: "This season, we'll be diving into Hen's true character. And you know, they say true character is built in crisis — and and our show is not short on crisis."

Previewing tonight's episode, Thoms tells EW "it's a doozy. It's high-octane and very emotional. We get to see Karen at work, it just happens to be the worst day of work ever."

Season 6, episode 6, "Tomorrow", airs Monday at 8 p.m. ET on Fox.

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