Spoilers ahead for the penultimate episode of 9-1-1 Season 3, called "Powerless."
9-1-1 was pretty standard for a few of its cases throughout "Powerless," although the heroes of Station 118 breaking into a walk-in freezer while "Ice Ice Baby" played over the scene was definitely a standout. The episode took a very serious turn when Athena was assaulted while investigating the case of a serial rapist. Her attack was being broadcast over her 911 call, allowing Bobby to listen. Based on footage from the Season 3 finale, this may result in one first responder leaving, and Athena isn't the only one possibly bowing out.
Athena was fortunately awake and on the mend by the end of "Powerless," although likely to remain in the hospital for several more days. Meanwhile, Karen began to suspect that Hen was having an affair after Hen was lying about credit card charges and getting unexplained texts from another woman. The good news is the truth was far less upsetting than an affair: Hen is considering going to medical school, and Chimney was upset at the prospect of losing his partner.
The trailer for the next episode of 9-1-1, which just so happens to be the Season 3 finale, reveals Athena possibly leaving the LAPD and Hen nowhere to be seen. Take a look:
While Hen can't be found on the scene of the train crash in the trailer, 9-1-1 fans shouldn't assume that she has already left her job as a paramedic behind. The Season 3 finale seemingly picks up more or less where "Powerless" left off, so that's not exactly enough time for Hen to start med school, if that's even the direction 9-1-1 wants to go with her character.
It will apparently be enough time for Athena's face to heal and for her to decide she's ready to give up the badge after 30 years of service, though, so we probably shouldn't make any assumptions just now. At this point, it's not even guaranteed that Athena and particularly Hen will get much screen time in the finale. And who's to say that Athena won't change her mind and choose to remain on the force?
The final episode of Season 3 will deliver the long-awaited return of Connie Britton as Abby, and her return seemingly will make the train catastrophe even more difficult for one character. Abby has gotten engaged in the two years since splitting with Buck, and Buck hasn't gotten much in the way of closure. Hopefully the meeting with Abby will help him move on and embrace new opportunities in Season 4.