Jamie and Eddie find themselves at odds when Jamie learns that Eddie's close friend Tracey may be using the restaurant she owns as a drug front. Also, Erin forms an alliance with Anthony and her ex-husband, Jack Boyle, when she is accused of causing the suicide of a former colleague; Frank weighs whether he should fire a female officer who has an online profile featuring naked photos of herself; and Danny and Baez try not to be influenced by their own biases when they are faced with various descriptions of the same suspect.

Danny and Baez investigate a case of grand larceny tied to feuding crime families when the gifts are stolen during a mob wedding. Also, Frank clashes with Mayor Chase when an influx of immigrants arrive in the city; Erin questions whether her district attorney campaign is compromising her day job; and Eddie enlists Jamie's help to bust a drug dealer responsible for fentanyl overdoses in order to comfort a grieving grandfather.