In a two-show crossover event with "Chicago P.D.," (Season 7 Episode 15 - Burden of Truth) a series of teen opioid overdoses sees Severide partner with Sean Roman, but begins to suspect there's more to the story than his old friend is telling him. Casey tries to be there for Brett as she considers her birth mother's offer to meet.
- Jesse Spencer as Lieutenant/Captain Matthew Casey
- Taylor Kinney as Lieutenant Kelly Severide
- Kara Killmer as Paramedic Sylvie Brett
- David Eigenberg as Firefighter Christopher Herrmann
- Joe Minoso as Firefighter Joe Cruz
- Christian Stolte as Firefighter Randy "Mouch" McHolland
- Miranda Rae Mayo as Firefighter Stella Kidd
- Eamonn Walker as Battalion Chief Wallace Boden
- Annie Ilonzeh as Paramedic Emily Foster
- Sean Roman appears in this episode.
- The plot will be concluded in a Chicago P. D. episode Burden of Truth.
- Brett meets her birth mother.