After its first several seasons, it felt like the only way “Chicago Med” could possibly outdo itself would be to take its threats to human life to a broader potential range of victims. Sure enough, a triple-dipped crossover with “Chicago Fire” and “Chicago P.D.” did exactly that. 

Each of the “One Chicago” programs’ casts stood to lose everything when it came to “Infection, Part II,” the fourth Season 5 “Med” episode, in which the city of Chicago found itself suffering greatly at the hands of a contagious flesh-eating bacteria, later suspected to be a possible bioterrorist attack. Forced into quarantine, Halsted and Goodwin veer dangerously close to succumbing to the unknown virus.

Even without the context of the global COVID-19 pandemic (the episode aired in 2019), the thought that bioterrorism could happen on such a scale was terrifying enough. The action is feature film in length, spread out across three episodes that extended the suspense and horror — “Part 1” aired on “Chicago Fire,” “Part II” on “Med” and “Part III” on “Chicago P.D.,” but it’s the “Med” episode that really pushed the limits of the series. Overall, there was a particularly unique feel to the fact that the entirety of “One Chicago” could be in trouble, making this miniseries so compelling.