With Chicago Fire, Chicago Med and Chicago P.D. taking over Wednesday nights on NBC, this year's crossover event is poised to be the biggest one yet. The three-hour event will see One Chicago's stars unite to take on a dangerous blaze that leaves a number of victims in its wake, including someone from Truck 81. Brace yourselves, it's going to be one stressful night.

"One of the Chicago Fire family is injured and needs to be tended to by Ava and Connor," Colin Donnell told TV Guide, although he refused to give any clues as to who. The tense situation will become even more nerve-wracking as Med doctors clash with the Fire crew, who have some strong opinions on how one of their own should be treated in the ED. Let's hope that they can settle their differences quickly because there are lives at stake here!

One Chicago Crossover Exclusive: A Fire Gets Personal for Halstead

And while this year's crossover will be packed full of drama, the event will also bring old friends together, including Fire's Severide (Taylor Kinney) and Med's April (Yaya DaCosta) who haven't spent much time together on-screen since April's debut in Fire's third season. "In the crossover, they interact more than usual," Yaya DaCosta teased. With a firefighter's life hanging in the balance, it looks like these two are reuniting under the worst of circumstances.

Equally stressed are P.D.'s Jay Halstead (Jesse Lee Soffer) and his brother, Med's Will Halstead (Nick Gehlfuss), who quickly realize their aging father was among those injured in the blaze. When the dust clears, it will be up to Jay and the rest of Intelligence to figure out who started the fire that sent so many people --including their dad — to Chicago Med.

See the official descriptions for all three episodes below.

Chicago Fire
Airdate: Oct. 3 at 8/7c (special time)
Description: Firehouse 51 is faced with a daunting challenge when an out-of-control blaze consumes a 15-story apartment complex, trapping victims on the top floors. Complicating the rapidly escalating situation, members soon discover that someone close to home may be one of the trapped victims.

Chicago Med
Airdate: Oct. 3 at 9/8c (special time)
Description: The doctors and nurses of Chicago Med find themselves on high alert when an overflow of patients are rushed into the doors following a terrifying apartment complex blaze. Dr. Rhodes fights to save the life of one of "Chicago Fire's" own, while Dr. Halstead and his brother Jay struggle with their own personal battle.

Chicago P.D.
Airdate: Oct. 3 at 10/9c (special time)
Description: After discovering the true cause of the high-rise fire, Intelligence races to find the man responsible. And for Halstead, it's personal.

The One Chicago crossover event airs Wednesday, Oct. 3 on NBC starting with Chicago Fire at 8/7c, followed by Chicago Med at 9/8c and Chicago P.D. at 10/9c.

Taylor Kinney, <em>Chicago Fire</em>Taylor Kinney, Chicago Fire