Sonequa Martin-Green (Star Trek: Discovery) is joining the cast of Boston Blue, CBS’ universe expansion of the long-running Blue Bloods.

Martin-Green will star opposite Donnie Wahlberg in the new series from writers Brandon Sonnier & Brandon Margolis (S.W.A.T.), Wahlberg will reprise his role as NYPD Detective Danny Reagan as he takes a position with Boston PD. He, together with Martin-Green, revealed that she was joining the fall show at a press conference Wednesday at Paramount.

Martin-Green will play Detective Lena Silver for the Boston PD.

“I’m gonna have to get a really good Boston accent, just so I can throw it out at times,” Martin-Green told reporters. “We love the Reagans. We have all loved the Reagans for so long. Being Detective Lena Silver, who is coming from a prominent law enforcement family, you will love the Silvers too. I’m super excited for this partnership, and to be back in the CBS family.”

Boston Blue is produced by CBS Studios in association with studio-based Jerry Bruckheimer Television. Sonnier and Margolis will serve as showrunners and executive produce alongside Jerry Bruckheimer and KristieAnne Reed of JBTV as well as Wahlberg.

While CBS and CBS Studios, which produced Blue Bloods, had explored spinoffs from the popular procedural drama, including one that would’ve had Danny Reagan move to Texas and another one with Tom Selleck, Boston Blue was not conceived as a Blue Bloods offshoot.

It originated with Sonnier and Margolis, along with JBTV, pitching CBS Studios and CBS a drama, then called Jamaica Plain, that follows a family of police officers in Boston whose eldest daughter is partnered with a new transfer from LAPD. The network ordered a script based off that pitch, sources said.

The script was well received at both the network and the studio, whose executives saw the Boston family police drama project as an opportunity to make it part of the Blue Bloods universe by bringing in a character from the New York family cop drama.

Given Boston native Wahlberg’s deep ties to the city, CBS and CBS Studios zeroed in on Danny Reagan and approached the Boston Blue creative team about changing the LAPD transplant character to a NYPD one, Danny.

“I’m incredibly grateful for the years on Blue Bloods, and incredibly grateful to be able to keep the the traditional Blue Bloods alive and move it forward into a new worth with new friends and new situations,” Wahlberg told reporters today. “We are really really working on this universe in a way that I think the Blue Bloods viewers are gonna be very happy, very excited, and a whole new world of viewers are gonna be able to discover us, too. “