There's a shift in show order for the crossover event. “Chicago Fire” will air first at 8 p.m., followed by “ Chicago Med “ at 9 p.m., with “ Chicago P.D .” concluding the event at 10 p.m.

NBC’s One Chicago airs its first crossover in five years tonight. Here’s how to watch the epic event featuring "Chicago Fire," 'Chicago Med," and "Chicago P.D.."

LaRoyce Hawkins of "Chicago PD," "Chicago Fire's" Miranda Rae Mayo, and Darren Barnet from "Chicago Med" talk about the first Wednesday night "One Chicago" crossover event in more than five years. The casts of all three shows will combine for a full three hours of pulse-pounding prime time action.

It’s three hours of the One Chicago dramas tonight, Wednesday, Jan. 29. And this is not like the usual three-hour block. We have the One Chicago 2025 crossover event happening! Yes, we have what will feel like a three-hour movie tonight.