Chicago P.D. Season 7, Episode 4 – "Infection, Part III". Episode Overview
Chicago Fire Season 8, Episode 4 – "Infection, Part I" . [S8E4] Infection, Part I
As panic grows, the city's heroes face a race against time to identify the source of the bacteria before it becomes a full-blown epidemic. Where to Watch Chicago P
Chicago Med Season 5, Episode 4 – "Infection, Part II" . Chicago P.D. Season 7
A rare but deadly "flesh-eating" bacteria begins spreading rapidly across the city .
is the fourth episode of Season 8 of the action-drama series Chicago Fire . It serves as the opening chapter of a massive three-part crossover event within the Chicago franchise, involving characters from Chicago Fire , Chicago Med , and Chicago P.D. . Crossover Viewing Order