Ep 5. Lost and Found

Danny and Baez investigate a possible serial killer who sends a chilling message to Danny. Meanwhile, Erin considers becoming a judge; a mayoral candidate claims that Frank has been secretly investigating her spouse; and Eddie confronts her dad when he turns up in the hospital. As Danny and Baez continue their investigation into the serial killer, they come across a man named John, who claims to have valuable information. However, John insists on speaking only with Danny, and he has a personal connection to the detective.

While Danny and Baez chase down leads on the possible serial killer, Erin is approached by a colleague who suggests that she consider running for a judgeship. Erin is hesitant at first, but the more she thinks about it, the more appealing the idea becomes. However, Erin's father, Frank, is less than enthusiastic about the idea, and she must weigh the potential benefits against the drawbacks of running for office.

Meanwhile, a candidate for mayor accuses Frank of using his position to investigate her husband, a wealthy business tycoon. Frank denies the accusation, but the candidate becomes increasingly hostile toward the NYPD. With tensions rising, Frank must find a way to protect the department's reputation while still ensuring that justice is served.

Finally, Eddie confronts her estranged father, who has been hospitalized following an injury. Eddie has mixed feelings about her dad, who abandoned her and her mother when Eddie was a child. However, when Eddie's father reveals that he has made amends for his past mistakes, Eddie is forced to confront her own feelings of anger and resentment.

As the episode draws to a close, Danny and Baez confront a shocking revelation about the serial killer case, while Erin must decide whether to pursue a judgeship or remain in her current position. Meanwhile, Frank must navigate the tricky waters of political intrigue and Eddie must come to terms with her complicated relationship with her father. In the end, the characters of Blue Bloods learn that the past can't always be erased, but it can be overcome with perseverance and determination.