The tense promo video above begins with Firehouse 51 arriving at the scene of an accident where one truck has hit another track in the rear. “It’s raining gas in there,” Severide says as the video shows gasoline dripping on the scene. One would think that would deter someone, but not Kelly. With a victim stuck in the truck, Kelly jumps into action and enters the truck, which could explode at any time. Gasoline makes the rescue hard to pull off because the firefighters cannot use devices that’ll spark. “One spark, and this guy gets incinerated,” Chief Pascal warns. Given Kelly’s risk in this rescue, he gets interested in the case on a deeper level. He realizes something is amiss with this accident and several others before it.

The episode also promises to be heavy on the Violet-Carver drama as Violet celebrates her birthday and Carver is torn about whom to offer his support. Jake Lockett previously teased some drama in this relationship, and given Violet and Tori’s spat in the previous episode, this is an excellent place for the drama to start. But whether they end up together this season, Lockett spoke about that, saying,

“In a world where they end up together, which I don’t know what that situation is — we haven’t had that in the scripts — I think he just needs someone who’s willing to meet him where he’s at. I think it would have to be a lot more care on her part and willingness to be honest about where she’s at.”

Will Severide get out before the “incinerator” explodes? What situation tests Carver’s allegiances? Find out when “Down the Rabbit Hole” airs on NBC tonight, Wednesday, October 23. You can also catch up with past episodes on Peacock.