Brace yourselves, next week's Chicago Fire will be a doozy.

The two-hour event will be comprised of back-to-back episodes and see familiar faces drop by including Chicago P.D's Antonio (Jon Seda) and Burgess (Marina Squerciati) along with Will (Nick Gehlfuss), April (Yaya DaCosta) and Ethan (Brian Tee) from Chicago Med. The brave firefighters of the firehouse will need the extra help after they find themselves on a dangerous call that takes a turn for the worse.

The crew heads to the scene of a house fire where, unbeknownst to them, there's an active shooter inside — adding an additional element of danger to their already risky jobs. And while our brave firefighters have managed to escape many a life-threatening situation before, it looks like they won't be so lucky this time around. Someone's getting shot and, according to showrunner Derek Haas, the show isn't afraid to see where the story might take them, even if it means potentially losing a firefighter.

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"I think one of the things that has set our show apart over five seasons is that we're not afraid to have some of our shocking events actually pan out," Derek Haas tells TV Guide. "This two-hour event's gonna be a big turning point probably in our show."

There are two very big reasons to speculate that someone's about to die on Fire. First of all, it's been a while since a major character has died. Though we've seen firefighters come and go at Firehouse 51, we haven't had a major firehouse death since Season 2 when EMT Leslie Shay (Lauren German) was killed by an arsonist with a vendetta and candidate Rebecca Jones (Daisy Betts) took her own life. And while Fire did tempt fate at the end of Season 5 with that gnarly warehouse fire that almost claimed the lives of Casey (Jesse Spencer) and Mouch (Christian Stolte), everyone from Rescue Squad 3 and Truck 81 made it out alive. With the two-hour event expected to be a game-changer, it sounds like someone's luck is about to run out.

Secondly, a new firefighter named Jake Cordova (Damon Dayoub) is headed to Fire on March 29, the week after the two-hour event, to claim an open spot on the team which doesn't bode well for one of our heroes. His arrival won't be a particularly positive one for the crew as they'll still be reeling from the events of the previous episode. "Because of the circumstances that surround his arrival, he's not going to be well-received," Haas explained. "And he's got a little bit of an attitude himself."

How he'll eventually fit in with the crew remains to be seen but judging from what we know about him so far, Cordova could be trouble for our heroes.

Chicago Fire's two-hour event airs Thursday, March 22 a 9/8c on NBC.

Taylor Kinney and Eamonn Walker, Chicago FireTaylor Kinney and Eamonn Walker, Chicago Fire