Boston Blue Season 1, Episode 17 Recap: Bridget Moynahan's Erin Reagan Returns - TVLine

John Medland/CBS At the end of Friday's "Boston Blue," Danny (Donnie Wahlberg) accompanies Erin (returning guest star Bridget Moynahan) back to New York City for a Reagan family dinner — which, alas, happens off screen. First, though, the siblings take down a serial killer and rescue his latest victim. Along the way, it becomes clear that not everyone is on board with Danny's move to Massachusetts. It's Abraham (Erin Gann) who tries to drive a wedge between brother and sister as they escort him to the bus depot where he abandoned the young girl he abducted. He needles Danny about leaving New York and, in the process, exposes Erin's mixed feelings, pushing her to admit that the family — herself included — isn't quite as "fine" with his move as she initially claimed. At one point, Abraham even misleads them about the victim's location, falsely suggesting she's in New York instead of Boston, while name-dropping Danny's brother Jamie to further get under his skin. Later, on the drive to New York, Erin insists she was only telling Abraham what he wanted to hear, and that she isn't actually disappointed in Danny for leaving — though she's not especially convincing. She does note that "everyone is going to be thrilled" to see him at dinner, "at least for one Sunday," suggesting he hasn't been back since his departure in the pilot. CBS screenshots On the morning of Rev. Peters' heart operation, Mae honors his wish and tells Lena about her biological father — Chris Williams ("Dexter" alum Erik King), an ex-con once arrested for armed robbery. Mae says she never told Chris she was pregnant, but leaves out one key detail: he later turned his life around and is now a small-town police chief just outside of Boston. Lena uncovers that on her own and drives to confront him at his precinct... only to find he's off that day. Instead, she meets Detective Asher Reed (Douglas Nyback), who has worked under Williams for a decade — though neither realizes just how closely their lives are connected. Chris, meanwhile, shows up at Mae's door after Reed tips him off that a Det. Lena Silver came looking for him. Their conversation makes it clear that Chris has known about Lena all along, and that there's another secret still being kept: he has a second daughter, Christina (Alisha Wainwright, best known for "Shadowhunters" and "Raising Dion"), making her Lena's half-sister. When Christina arrives at the precinct to meet her husband — Reed, who we now know is Lena's brother-in-law — Lena puts the pieces together and makes a quick exit. (TVLine, meanwhile, can confirm that King and Wainwright will each return in one additional episode before season's end.) What did you think of "Boston Blue" Season 1, Episode 17: "L'dor Vador"? Drop your thoughts in a comment below.