Chicago P.D. - Season 3 Episode 10 -

A doctor with personal connections to Voight is under investigation when four of his patients are committed to Chicago Med after an overdose of chemo. The doctor denies Lindsey and Halstead access to his files, but after obtaining a warrant the team is able to track down his patients and discover all of them have been poisoned with unnecessary chemo. Meanwhile, Burgess and Platt work together to clear Roman's name. (The Beating Heart (1) aired on Chicago Fire, season 4, episode 10. Malignant (2) aired on Chicago Med, season 1, episode 5.)