[s8e4] Infection, Part I Apr 2026

: Firehouse 51 responds to a major fire at Central Chicago University . While inside, Kelly Severide notices a laboratory wall bearing the same "BRT" initials the original victim mentioned.

As the medical crisis unfolds, the teams begin to suspect this isn't a natural occurrence. [S8E4] Infection, Part I

: A man named Stuart Anderson suddenly collapses, revealing a gruesome infection on his leg while chanting the letters "BRT" . : Firehouse 51 responds to a major fire

: Shortly after, Ambulance 61 discovers two more victims dead from the same infection in a private residence. : A man named Stuart Anderson suddenly collapses,

( S8E4 ) serves as the explosive opening to a massive three-part One Chicago crossover event, weaving together the worlds of Chicago Fire , Chicago Med , and Chicago P.D. .

: Additional cases surface, including a woman and her child at a gas station, leading the CDC to step in as the situation escalates into a full-scale city epidemic. Investigation and Suspicion