'Blue Bloods' Uncovers a Major Family Secret in Season 10 Finale (RECAP)

Blue Bloods Season 10 Finale Family Secrets Recap
Spoiler Alert
John Paul Filo/CBS

[Warning: The below contains MAJOR spoilers for the Season 10 finale of Blue Bloods, "Family Secrets."]

If the end of "Family Secrets" gave you déjà vu, it's probably because it made you think of the Blue Bloods Season 8 finale and that family dinner.

The unintended Season 10 finale saw the Reagans learn about a new part of their family, as Sean's (Andrew Terraciano) school assignment timed with a visitor for Frank (Tom Selleck) leads to a surprising discovery.

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And while Danny (Donnie Wahlberg) and Baez (Marisa Ramirez) prove that Erin's (Bridget Moynahan) key witness' death was caused by the person he was testifying again, Jamie (Will Estes) and Eddie (Vanessa Ray) deal with a much more personal case. After finding a baby left in a duffel outside the precinct, Eddie gets attached (and even names him) and they uncover an adoption ring. And as Jamie tells her in the end, there is a way to get a baby that's theirs to keep...

But for now, let's break down the big family secret that disrupted Frank's day.

It Was Supposed to Be a Regular Day...

Sean's a bit panicked when he stops by to see Frank. What was supposed to be a regular school assignment about his family ancestry resulted in a DNA match to a male first cousin from Frank's side of the family. But his grandfather is certain he'd know if anyone in the family had a skeleton in their closet.

Blue Bloods Season 10 Finale Frank Office

(John Paul Filo/CBS)

He's proven wrong when a woman, Paula (Bonnie Somerville), he knew a long time ago stops by to request that her son be transferred out of the fire arms unit. Why? "Because your son Joe was his father," she reveals. "And because as his mother, I'd like him to have a safer assignment."

Not a Skeleton, But a Real-Life Guy

Paula dropped out of the academy because she was pregnant. Joe didn't know, she says, because she wasn't interested in being in a relationship with him. But now her son is asking about his father and doing DNA testing.

Frank has Gormley (Robert Clohessy) give him the rundown on Joe Hill (Will Hochman). His grandson graduated the academy in 2016, and he moved to the FIU after four years. He intervened in a bodega robbery, subdued the perp without injury, saved a woman and her baby, and was given is choice of assignment. Frank has Gormley set up a meeting, but after the other man leaves, Baker (Abigail Hawk) pushes the commissioner on what's on his mind. He confides in her about Joe, and while he's unsure about how to proceed, he plans to do so "with care for all concerned."

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'It is a quintessentially Reagan story; a deeply personal one for Frank,

Frank stands facing the window when Joe comes in for the meeting, and the entire time, it's pretty obvious that he's taken aback by having his grandson in front of him. Frank starts with small talk about his latest operation before turning to his request for the fire arms unit.

"I didn't join the department to get cats out of trees, you know what I mean?" Joe asks and notes that the job runs deep in his boss's family. Yes, it runs deep in his family, too, the young detective agrees, but "not like you Reagans." Since it's clear that Joe has no idea they're related, Frank claims he's just meeting with members of specialized units. But before Joe leaves, Frank notes that he's wearing the color of the day and how important that is and advises him, "watch your six."

Donnie Wahlberg Blue Bloods Season 10 Finale Danny

(Patrick Harbron/CBS)

"It Was Familiar"

Frank calls Erin, Danny, Jamie, and Sean over to join him and Henry (Len Cariou) and gets right to it: "Joe fathered a son he never knew about." Sean assures them it can't be a scam; the company is the same one used for crime scenes and very accurate.

What's he like? "I just met the guy, and he's my grandson," Frank says. "I will say this. He carries himself in a certain way, the way he kind of sets himself before he's going to say something, you know what I mean?" Danny does, and Henry even gestures to him.

It was "familiar, same way he talked about being on the job," Frank continues. "Like all of you when you first came on. Being a cop was like playing for the Bulls with Jordan or the drums with Springsteen. It was just familiar."

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All that's left to do is meet him as his family, but how will he feel about them being Reagans? "He's one of us, he'll be fine," Henry insists. And with that, they decide to invite him to Sunday dinner.

And the Reagans Are Joined By (a) Joe Once Again

That plan hits a snag when Paula learns that Frank isn't going to transfer her son to a safer assignment. For now, she'd rather he not contact them, and she's sorry Joe ever found out about them.

But Joe still comes to Sunday dinner, with Sean, and he meets his family. He hopes it's okay he's there, he tells his commissioner, who assures him "it's more than okay. And call me whatever you want ... except sir." And with that, he sits down and joins them for grace.

Tom Selleck Blue Bloods Season 10 Finale Sunday Dinner Reagans

(John Paul Filo/CBS)

Will Joe become a permanent member of Sunday dinner with the Reagans? We'll have to wait and see.