Holy crap, everyone on Chicago Fire is in very grave danger!

Wednesday's finale, titled "I'm Not Leaving You," ended with most of Ladder 81 trapped in a mattress factory basement that was about to explode. Brett (Kara Killmer) and Foster (Annie Ilonzeh) were upstairs helping to evacuate the smoke inhalation victims, but the rest of the firehouse was down below either trying to stop an old boiler from exploding and taking out the whole block or trying to free a half-dozen workers who were trapped in a locked room.

The final moment of the episode showed the pressure gauge on the boiler cracking. This couldn't be worse timing, because Brett and Casey (Jesse Spencer) hit a major snag on their road to hooking up. Despite noticeable sparks throughout the season, the two went into the fire further apart than ever after Brett said yes to Kyle's (Teddy Sears) surprise proposal. She wouldn't have accepted it if Casey hadn't told her that she and the chaplain are so good together, forcing her to think that Casey wasn't interested in her at all. If he had just waited a beat before making the proclamation, he would have found out that Kyle was actually telling Brett that he got a new job out of state. Instead, he pushed her into another man's arms, and we could scream.

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Will this latest explosion help both of them see how much they truly care about each other? We'll have to wait until Season 8 to find out if Casey survives in order to go after his girl.

However, they're not even the most bittersweet couple in jeopardy. The first half of the episode found Severide and Stella teaming up to resolve Benny's old case, and that intimate time together forced the pair to drop all pretenses and finally admit they still had feelings for each other. After Stella helped track down the arsonist and Carol Spears was successfully handed over to the police, there was nothing standing in the way of the estranged couple getting back together. Severide promised to be the man that Stella deserves from now on, so naturally, they decided to quite literally reconnect in his cabin. It was a sweet moment that anchored one truly wild and gripping hour. But Severide is also stuck down in the basement of the factory, potentially blown to smithereens. Can Season 8 come sooner?

Chicago Fire returns this fall on NBC.

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Kara Killmer and Jesse Spencer, <em>Chicago Fire</em>Kara Killmer and Jesse Spencer, Chicago Fire