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.

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.

One Chicago made some notable changes to its schedule for the January 29 crossover event. The regular order of shows was switched around, so that Chicago Fire kicked off the action instead of airing second,

Between the gripping three-part One Chicago crossover, turmoil at the hospital, and several newcomers making themselves at home at Gaffney, Season 10 of Chicago Med has been delivering some seriously intense drama and action.