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

For the first time in five years, “Chicago Med,” “Chicago Fire” and “Chicago P.D.” are crossing over on Jan. 29. Here's how to watch the episodes and the order they're in.

P.D.' showrunner Gwen Sigan promises 'some really fun character pairings between all three shows that are unexpected.'

One Chicago has once again shown why it's one of the most beloved franchises on television. The recent crossover event, which took place on Wednesday, January 29 on NBC, drew in millions of viewers, setting audience records for the season.