Here's How 'Chicago PD' Will Crossover with 'Chicago Fire'

Chicago P.D. is celebrating its 100th episode with a Chicago Fire crossover.

The special event is set to air in early March and will kick off with the milestone Chicago P.D. hour before concluding the following night on Chicago Fire. It is also rumored that the cast of Chicago Med, which returns for its third season next month, will appear in the crossover event.

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While the cast and crew aren't spilling too many details on the specifics of the crossover, Chicago Fire showrunner David Haas did let TVLine in on a few secrets at the annual #OneChicagoDay event.

According to Haas, the storyline involves "P.D. taking over Firehouse 51 for the second part of [the crossover], on a stakeout kind of a situation." He also teased that the two-part event will have "fun parts to it" and "conflict."

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This won't be the first crossover event in the Chicago series. In March, there was a three-hour crossover between Chicago Fire, Chicago P.D., and Chicago Justice. Chicago P.D. has also crossed over with Dick Wolf's Law & Order: SVU on multiple occasions.

An official date has not yet been set for the crossover event.

Chicago P.D. airs Wednesdays at 10 pm ET on NBC. Chicago Fire airs Thursday at 10 pm ET.