[Warning: The following contains spoilers for Chicago Fire's fall finale, titled "Always a Catch." Read at your own risk!]

If it wasn't obvious by now, Chicago Fire's shocking fall finale pretty much confirmed showrunner Derek Haas thrives off of messing with our emotions. Wednesday's stressful hour had our hearts working overtime thanks to a massive road accident, Stella (Miranda Rae Mayo) and Severide (Taylor Kinney) falling out over Stella's buddy Tyler (Tye White) and Casey's (Jesse Spencer) apartment going up in flames. Raise your hand if you felt personally attacked by the end of this episode.

Things were already heating up between Casey and Naomi (Kate Villanova) before they embarked on a road trip to investigate a treacherous manufacturing company and that extra time together erased all doubts about whether or not they'd get past their harmless flirting and into something more concrete. Reeling from the excitement of confronting a group of shady business owners face-to-face, the pair locked lips before getting hot and heavy back at Casey's apartment.

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But alas, that unexpected hookup might not have been the perfect remedy for moving on from a serious relationship. Casey's romance with Dawson was epic and it will take time for things not to feel weird, which is why we're not surprised he woke up the next morning looking super regretful. Whether or not that worried face was the result of him feeling guilty about moving too fast with Naomi or just a firefighter sensing the immediate danger in the next room remains to be seen. What's clear is that Casey faces serious danger ahead after his apartment was set ablaze. According to Haas, you should be "very worried" for his life, as well as Naomi's, in the second half of the season. "Somebody is trying to kill Casey and Naomi," he tells TV Guide.

We have a strong feeling the culprits are the shady executives who weren't too thrilled about Naomi's exposé on their faulty trailer equipment, which has already led to numerous death. Either way, this couldn't come at a worse time for Casey, who's still figuring out what he wants with Naomi after his marriage to Gabby pretty much crashed and burned. But now that they've found themselves on the wrong end of a Molotov cocktail, expect the pair to stick together for the time being, especially since Naomi isn't going anywhere anytime soon.

Elsewhere, Stella and Severide were forced to confront the scary reality that this workplace romance is a lot harder than they initially thought. Still grieving over his father's sudden death, Severide was not at all receptive to Stella's attempts to get him to hang out with her friend Tyler as a way of taking his mind off things. Instead, Severide wound up accusing her of leading her old buddy on romantically. That small argument escalated into a massive blow up that ended with Stella walking out on him. The huge fight may have left Stellaride on the rocks, but don't count them out just yet. Per Haas, they're far from over.

"I would say they're on the ropes. They're not done at the end of this finale. They're reeling," he said.

But that's not the only good news for Firehouse 51. The crew also came together to support Cruz (Joe Minoso), whose new girlfriend Chloe (Kristen Gutoskie) wound up at Chicago Med in critical condition following a gnarly road accident. In one of the episode's most touching scenes, her parents thanked Cruz for bringing such joy to her life (and our lives, really) after learning that she's expected to pull through.

Plus, Brett (Kara Killmer) finally asked the firehouse's hunky new chaplain, Kyle (Teddy Sears), out for dinner — sorry, Brettonio shippers! — and we're already picking out their baby names.

Brace yourselves for a bit of a wait. New episodes of Chicago Fire arrive in 2019.

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<p>Jesse Spencer, <em>Chicago Fire</em> </p>

Jesse Spencer, Chicago Fire