Platt (Amy Morton) should've just been having dinner with her father (Chelcie Ross) and telling him to be wary of his new young girlfriend Natalie (Lilia Vassileva). But she's attacked when returning to her car and the assailant escapes with her gun.
While Dr. Rhodes (Colin Donnell) treats Platt at Chicago Med, Mouch (Christian Stolte) confesses that Platt was threatened the week before and the team sees her having words with an agitated liquor store owner, who says Platt came by prior to her dinner date to personally help him out. But when the team follows up at Platt's father's house, he too has been attacked and killed.
Lindsay (Sophia Bush) is convinced that Platt has an offender in mind, leading her to Natalie and Natalie's ex-boyfriend Leonard Millwood. Natalie is arrested trying to use one of Robert Platt's credit cards and Leonard is taken into custody in the store's parking lot. When they're interrogated both claim they didn't kill anyone, and it's proven that Robert was transferring ownership of all of his companies to Platt.
Olinsky (Elias Koteas) and Atwater (LaRoyce Hawkins) return to the nightclub a block away from where Platt was attacked, and get video of a car circling the block. The team identifies it as belonging to ex-con Wade McGregor, and his arresting officer admits that Platt gave her an anonymous tip that led to the bust.
Platt then goes rogue and escapes from Chicago Med so that she can catch McGregor herself. She finds him at his house and then ties him to a chair, but before she can kill him Voight is there, confronting her and convincing her not to go through with it. McGregor is arrested while Platt goes back to Med and is tearfully reunited with Mouch.