Between a thrilling firetruck-ambulance-civilian truck chase and Foster's (Annie Ilonzeh) blowup with Brett (Kara Killmer), there were plenty of memorable moments in Chicago Fire's exciting midseason premiere on Wednesday. The episode, titled "Hold Our Ground," saw Casey (Jesse Spencer) track down missing firehouse equipment while Kidd (Miranda Rae Mayo) played mediator in Brett and Foster's interpersonal dispute. Plus, Gallo's (Alberto Rosende) contentious dynamic with a paramedic from a rival firehouse took a surprising turn when the pair wound up in bed together at the end of the night. Who else was sweating after that?

With much work to be done professionally, that left no time for Brett and Casey to address the obvious feelings they have for each other but refuse to act upon. Casey's recent hookup with Gabby (who returned to town for one episode) further complicated things too, with Casey still hung up on his ex and Brett reluctant to pursue a romance with the sandy-haired captain. Despite the setback, it looks like Brett and Casey will be spending plenty of time together in the near future.

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"This Gabby hookup gives Brett pause about where they could potentially go," showrunner Derek Haas teased to TV Guide. "But sometimes, circumstances force you into closer proximity than you would normally be, so I think you're gonna see some more Brett and Casey scenes in the immediate future."

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

Elsewhere, Severide (Taylor Kinney) enjoyed an eventful week. Not only did he survive a potentially disastrous encounter with a felony arsonist in a dark basement, but he was also "fired" from his post at OFI and promptly returned to the firehouse — right where he belongs. But although Severide might be back, there's still one lingering problem that might stir up some trouble with his girlfriend, Kidd, if he's not careful: Seager (Andy Allo) is unwilling to let him go just yet.

Seager continually reached out to the lieutenant for his insight on several open arson investigations throughout the hour, prompting Severide to reject her last call for help. Haas confirmed that while she respects him professionally, Seager's desire to keep working with him is also fueled by underlying romantic feelings.

"He was efficient and very good at what he did, so she looks at that and says, 'I would sure like to continue having a partner like that,'" Haas said. "But then, of course, it's also Severide, so she seems to be interested in him beyond professionally."

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Severide has been aware of this, of course, but remained friendly with Seager because he found her harmless. "He does dig her style and her professionalism and good work in the OFI department. He's only got eyes for Kidd, so he doesn't want to ruffle any feathers, but I think he's got one eye on what she's doing and is a little bit amused by it," Haas said, noting that Seager will likely be back.

It sounds like this tricky dynamic, exacerbated by Kidd's jealousy, isn't going to go away anytime soon. But Severide will need to keep a level head through it, because he'll soon be stepping into the role of best man for Cruz's (Joe Minoso) upcoming nuptials with Chloe (Kristen Gutoskie). The wedding is set to take place toward the end of the season, and at a site that hasn't been used before.

"We've used the firehouse before and Molly's and the courthouse, so we wanted to try something very unique for the Cruz-Chloe nuptials," Haas explained. "It wouldn't be Chicago Fire if everything went right straight from the beginning so expect a few curveballs."

Haas also revealed that Kidd will be among the wedding party, meaning that Severide and Kidd will be staring at each other from across the aisle. Raise you're head if you're hoping for a double wedding!

Chicago Fire airs Wednesdays at 9/8c on NBC.

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Taylor Kinney and Miranda Rae Mayo, <em>Chicago Fire</em>Taylor Kinney and Miranda Rae Mayo, Chicago Fire