Chicago Fire will be attacked from "inside" during season 12 finale

There's a lot riding on the season 12 finale of Chicago Fire. Granted, dramatic season finales are par for the course in the One Chicago franchise, but this particular episode will seemingly shape the way Firehouse 51 operates moving forward.

51 has struggled to find consistent team members to fill the medic and firefighter roles, and part of this is due to the string-pulling of one Chief Robinson (Laura Allen). She has been targeting 51 for the whole season, with the seeming intention of taking over as Deputy Commissioner when the current one retires.

Andrea Newman teased a season 12 betrayal

She sees Chief Boden (Eamonn Walker) and the rest of 51 as a threat, and is trying to dismantle what makes them a uniquely powerful firehouse in the city. She sent Jared Lennox (Wesam Keesh) to try and sabotage the promotion of Violet Mikami (Hanako Greensmith) earlier in the season, and while he's gone now, Fire showrunner Andrea Newman suggests that there's more betrayal to come.

Newman recently discussed the season 12 finale with TV Insider, and dropped a bombshell detail that wasn't included in the synopsis. While fans already knew that Boden would be leaving 51 full time, we didn't know that there would be some political manipulation coming from within the firehouse. Here's what the showrunner had to say:

"51 has dealt with all kinds of outside conflict over the years… but when it comes to next season I keep thinking of a famous line from that old horror movie, When A Stranger Calls: It’s coming from inside the house."

Jack Damon is the most obvious suspect

Someone under 51's roof is not being honest about their intentions. There's an obvious suspect and a less obvious one. The former is Jack Damon (Michael Bradway), who took a phone call that all but guaranteed that he was up to no good. The latter, though, might be worth considering as fans enter the final episode: Lyla Novak (Joceyln Hudon).

Novak has been a well-liked character so far, and has even struck up a friendship with Violet, but we don't know that much about her yet. We could feasibly see an outcome in which Novak is revealed to have an ulterior motive for helping Chief Robinson, if for no other reason than she would be more of a shocking mole than the very suspicious Damon.

We hope we're wrong, but Newman's comments have made it clear that we need to have our guard up as we gear up for the season 12 finale.