| "Infection" | |
|---|---|
| Chicago crossover event | |
&sq=Envato&lang=en&file=File:Infection_crossover_promo_poster.jpeg) Promotional poster for the crossover event. | |
| Story by | Dick Wolf & Derek Haas |
| Original air date | October 16, 2019 |
| Part 1: Chicago Fire | |
| Episode title | "Infection: Part I" |
| Episode no. | Season 8 Episode 4 |
| Directed by | Reza Tabrizi |
| Teleplay by | Derek Haas |
| Episode chronology | |
| Part 2: Chicago Med | |
| Episode title | "Infection: Part II" |
| Episode no. | Season 5 Episode 4 |
| Directed by | Michael Pressman |
| Teleplay by | Diane Frolov and Andrew Schneider |
| Episode chronology | |
| Part 3: Chicago P.D. | |
| Episode title | "Infection: Part III" |
| Episode no. | Season 7 Episode 4 |
| Directed by | Eriq La Salle |
| Teleplay by | Gwen Sigan |
| Episode chronology | |
| Crossover chronology | |
| Preceded by | "February 2019 Chicago crossover event" |
| Followed by | "February 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.