Infection (Chicago franchise)

"Infection"
Chicago crossover event
Promotional poster for the crossover event.
Story by
Original air dateOctober 16, 2019 (2019-10-16)
Part 1: Chicago Fire
Episode title"Infection: Part I"
Episode no.Season 8
Episode 4
Directed byReza Tabrizi
Teleplay byDerek Haas
Episode chronology
Part 2: Chicago Med
Episode title"Infection: Part II"
Episode no.Season 5
Episode 4
Directed byMichael Pressman
Teleplay byDiane Frolov and Andrew Schneider
Episode chronology
Part 3: Chicago P.D.
Episode title"Infection: Part III"
Episode no.Season 7
Episode 4
Directed byEriq La Salle
Teleplay byGwen Sigan
Episode chronology
Crossover chronology
Preceded byFebruary 2019 Chicago crossover event
Followed byFebruary 2020 Chicago crossover event

"Infection" is a three-part fictional crossover event that exists within the Chicago television franchise. The event aired on NBC consecutively in three back-to-back one-hour time slots on October 16, 2019. It began with "Infection: Part I" of Chicago Fire, continued with "Infection: Part II" of Chicago Med, and then concluded with "Infection: Part III" of Chicago P.D. All three episodes followed a unified story line of an infection spreading across Chicago and the first responders dealing with the repercussions. Many actors in the franchise appeared outside of their main series and in all three parts of the crossover.