Bridget Moynahan joins Donnie Wahlberg in ‘Blue Bloods’ spinoff ‘Boston Blue’

Donnie Wahlberg is reuniting with a key member of the Blue Bloods family.

The New Kids on the Block star celebrated the announcement of his on-screen sister, Bridget Moynahan, joining him in the premiere episode of Boston Blue, his upcoming Blue Bloods spinoff that sees his former NYPD detective Danny Reagan solving crimes in Massachusetts’ capital.

“Reunited and [it] feels so good!” Wahlberg wrote on Instagram on Friday. “So excited to have my dear friend, and TV sister @bridgetmoynahan, join me for a special guest appearance in the premiere episode of #BostonBlue!”

Wahlberg also revealed that Moynahan will lend her talents behind the camera later in the season. “She’ll also be bringing her incredible directing talents to the show this season!” he wrote.

The actor teased the possibility of further Blue Bloods crossovers. “More fun (and surprises) to come,” he wrote. “Let’s go! ”

In a separate post on his Instagram Stories, Wahlberg continued to tease the addition of other Blue Bloods cast members. The actor reposted a comment that stated “Love to see your faces together again…who’s next,” and added a copious amount of eye emojis, indicating that fans should keep their eyes peeled.

On the original Blue Bloods, Moynahan played Assistant District Attorney Erin Reagan, the sister of Wahlberg’s Detective Danny Reagan. The on-screen siblings were two key parts of the broader Reagan law enforcement dynasty, which also included their brother Jamie (Will Estes), their father Frank (Tom Selleck), and their grandfather Henry (Len Cariou).

On Thursday, Wahlberg shared his gratitude for the Blue Bloods fans in a behind-the-scenes video teasing the new show. 

“I just wanna take a second to say how much I appreciate you all. For over a decade and a half, you’ve shown up and supported, and that means the world to me,” the actor said. “Boston Blue is a brand new chapter built on a strong foundation. It’s a different story with all the same heart and all the same love and all the same family at its core.”

Boston Blue will see Danny relocate to Boston, where he will be partnered with Detective Lena Silver (Sonequa Martin-Green), who is the eldest daughter of another major law enforcement family in the Northeast. Ernie Hudson will portray Lena’s grandfather, Reverend Peters, while Psych star Maggie Lawson is set to play Sarah Silver, the Boston P.D.’s superintendent. Meanwhile, Gloria Reuben will play Mae Silver, the Silver family matriarch, and Marcus Scribner will play Jonah, the family’s youngest member.

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The spinoff will also prominently feature Danny’s son, Sean Reagan, but he’ll be played by Mika Amonsen (Thanksgiving) instead of original actor Andrew Terraciano, who began playing Sean when he was seven years old.

Boston Blue premieres on CBS on Oct. 17.