Bridget Moynahan is reuniting with Donnie Wahlberg on the Friday, May 1 episode of Boston Blue, returning to the role of ADA Erin Reagan for the first time since the pilot. Her appearance puts another Reagan family name back into Danny’s orbit just as the season moves toward its final stretch.
The episode centers on Danny racing against time after a captured serial killer hints at where a missing child may be, with the detective teaming up with a familiar ally in Season 1, Episode 17. That setup gives Erin’s return immediate weight, because she has always been the one willing to push Danny when he would rather stand his ground.
Brandon Margolis said that a lot of what made Erin work was her habit of trying to take care of Danny even when he was too stubborn to notice, describing how she would walk into his hospital room, tidy it up and dare him to be angry with her. He added that Moynahan was “awesome to come play with us,” a nod to how naturally the character fits back into the show’s family-first world.
Boston Blue premiered on October 17, 2025, with Wahlberg reprising his Blue Bloods role as NYPD Detective Danny Reagan after taking a position with the Boston Police Department to be closer to his son, rookie patrol officer Sean, now played by Mika Amonsen. Danny has been paired with Detective Lena Silver, while the wider Silver family includes Mae Silver, Sarah Silver, Jonah Silver and Reverend Edwin Peters. Erin was last seen in the premiere, when she came to Boston to check on her brother and his comatose son Sean, and her return on May 1 arrives after guest turns by Len Cariou as Henry in Episode 13 and a breakup for Danny and Baez in Episode 15.
The timing matters because the show is already moving into its endgame, with the season finale scheduled for May 22 and Marisa Ramirez set to return as Maria. Boston Blue was renewed for Season 2 on December 3, 2025, making Erin’s comeback less a one-off nostalgia play than another sign the series is leaning hard into the Reagan family ties that still anchor it.