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Infection, Part III is the fourth episode of Season 7 of Chicago P.D. It is the conclusion of a three-part Crossover event with Chicago Fire and Chicago Med. The event starts with Infection, Part I, continues with Infection, Part II, and concludes with Infection, Part III.


After zeroing in on the suspect responsible for the bioterrorism that’s gripping Chicago, the PD prepares to undertake their biggest manhunt yet. Upton is torn between helping track down the perp and providing emotional support to the scared young girl that needs her. Voight fears his team is being sent on a wild goose chase.


Main Cast

Crossover Cast

Recurring Cast

  • Paloma Nozicka as Carrie Seldon
  • Anthony Ferraris as Tony
  • Alejandro Raya as Officer Caswith

Guest Cast

  • Aaron Serotsky as David Seldon
  • Kathleen Munroe as Dr. Andrea Danover
  • Eileen Galindo as Mama Alma Garcia
  • Kyla Kenedy as Amanda
  • Ben Wilson as Officer Murphy
  • Julian Hester as John Sorenstein
  • Louise Lamson as Dr. Heather Holcomb
  • Javier Gutierrez as Driver
  • Brett Lee as Shipp
  • Paul Zinke as Jordan
  • Sheri Winkelmann as Woman
  • Christopher R Ellis as FTO
  • Andrea Adams as Patrol Officer 1
  • Ricky Bartlett as Security Guard 1
  • Grant Stokes as Board Member 1
  • Scot Morton as Board Member 3