If you’ve been eagerly anticipating Boston Blue, the wait is over! The new police procedural kicked off tonight on CBS with a thrilling season premiere. In the first episode, viewers are introduced to the series protagonist, Danny Reagan, who Blue Bloods fans will immediately recognize.
Danny is an NYPD detective who finds himself moving to Boston for a reason that's shared in the first episode. While there, he partners with Lena Silver, a skilled detective with the Boston Police Department, who comes from a family deeply rooted in law enforcement.
Prior to the season premiere, news broke that a beloved Blue Bloods star would be making a cameo in the first episode. While this actor does appear in the premiere, another familiar face from the original series also makes an unexpected appearance. Find out who they are below!
Spoilers are ahead from Boston Blue season 1 episode 1.
Bridget Moynahan returns as Erin Reagan in the Boston Blue premiere
If you had been keeping up with all the Boston Blue news, you would have already known that Bridget Moynahan would be reprising her Blue Bloods role as ADA Erin Reagan in the spinoff series. Erin is Danny's younger sister. Donnie Wahlberg, who plays Danny, was the person to announce the news back in July 2025. He shared a photo on his Instagram of himself and Moynahan, and in the caption is where he revealed that she'd be making a guest appearance in the first episode.
In the season 1 premiere, Danny is forced to leave behind whatever he's got going on in New York to travel to Boston to be there for his son Sean, who is in a coma at the hospital. Sean is a rookie cop, along with his friend Jonah. While walking down the street one night, Sean and Jonah notice a nearby office building on fire. They rush in to save people trapped inside, but as Sean tries to escape, the fire catches up to him. Luckily, Jonah is able to drag him out, but the incident leaves Sean seriously injured and in the hospital.
Throughout the first episode, Danny works with Lena to crack the case behind who started the fire at the office building and who is responsible for the death of the CEO who owned the company housed there. In the midst of all this, he makes sure to visit Sean at the hospital. On one visit, he notices Erin in the room. Danny had told her not to come, but she ignored his warning, insisting on being there for her nephew and him.
Erin appears in a few more scenes in the episode and even meets Lena and her family during a Silver family dinner. But her reason for appearing in the episode is really just to check in on Sean and offer support to Danny. The last time we see her in the premiere is at the very end of the episode. As she and Danny are praying over their food in the hospital, Sean starts to wake up. While Danny rushes to his side to check on him, Erin runs out of the room to get help.
Marisa Ramirez returns as Maria Baez in the Boston Blue premiere
Marisa Ramirez’s cameo in the Boston Blue premiere came as a total surprise, but a welcome one. There were no prior reports about her reprising her Blue Bloods role as Detective Maria Baez in the spinoff. But although it was great to see her back on our screens, her appearance felt far too brief. We only see Maria at the beginning of the episode for a short scene.
After Sean ends up in the hospital, Danny receives a call about it. But guess where he was when he got the news. He was in his New York apartment with Maria, and judging by how little clothing they were wearing, the call clearly interrupted a private, intimate moment between them. Now, this scene will make a lot of Blue Bloods fans happy.
Danny and Maria were partners in Blue Bloods, and they had sort of a will-they-won’t-they relationship going on. In the series finale, Danny finally makes his move and asks Maria on a pizza date, to which she agrees. However, it was unknown if the date led to something more. Well, we got our answer in the Boston Blue premiere. Danny and Maria are officially together.
With Danny choosing to relocate to Boston, it does make us wonder how their relationship will handle the distance. Will Maria eventually move to Boston with her daughter? Fans would surely love that, but we'll have to wait and see how everything plays out.
A new episode of Boston Blue season 1 airs on CBS every Friday night.