Adding a new character to a well-established television series is always a risky gambit. For every successful choice — see the many, many recasts that have passed through the hallowed precinct halls in the “Law & Order” universe — there’s the risk of ruining things with a Cousin Oliver-style fresh face.

However, “Blue Bloods” scored an interesting and yet remarkably controversial character in the form of Joe Hill (Will Hochman). Part of the CBS show’s fourth generation of Reagan grandchildren, he was unique because he wasn’t raised with the rest of the family, consuming their iconic Sunday dinners and wrapped in the cosseting comforts of being watched out for on the force by other members of the family. However, being the son of the eternally revered late Joe Reagan automatically reserves him a seat at the family table. A family member who isn’t privy to their ways and traditions, he provides a fresh eye on the Reagan family’s typical behavior and sometimes rebels against it.

It is, unfortunately, a concept some fans also decided to take a stand against — especially when it was revealed that the saintly Joe Reagan had conceived a child out of wedlock and never knew about Joe Hill’s existence. Joe Hill is ultimately excised from the show after appearing somewhat regularly during Seasons 11 and 12 before fading away during Season 13. This is a crucial error the series ought to ameliorate while it still has time, especially with “Blue Bloods” closing in on its final season.

Joe’s youthful inexperience adds a new wrinkle to the show’s plot

It’s hard to make a newbie sympathetic and interesting to an audience that isn’t prepared to embrace them wholeheartedly, and it’s true that “Blue Bloods” did fall into this trap ever so slightly with Joe. During his first few appearances, he is a typical rebellious young hothead, bucking anything resembling adherence to procedures and rules. His rebellions are intended to make the audience question authority and change. To wit — he butted heads with everyone, from his grandfather Frank (Tom Selleck) to Uncle Danny (Donnie Wahlberg), about what’s right and wrong in the field. When his grandfather tries to take a methodical approach when Joe Senior’s gravestone is vandalized during Season 13, for instance, Joe Hill goes on the warpath immediately. It complicates things for Frank and makes the investigation more difficult.

But this is just the sort of backtalk the Reagan family desperately needs in their lives. One of the biggest weaknesses of “Blue Bloods” is that it tends to allow the Reagans total moral authority in their world — episodes where they’re allowed to be wrong are rare. Joe, however, frequently questions that authority, making him a worthwhile and interesting character.

He brought out something quite interesting in the show’s characters

Joe Hill’s persistent pushing didn’t just affect how “Blue Bloods” told its stories; it also moved the show’s characters to fresh heights of interesting behavior.

In reaction to Joe, Frank is forced to move more methodically in the field than ever, having become accustomed to life as a commissioner who simply and quickly gets what he wants. Joe’s presence also forces Frank to reconcile with the fact that his son, Joe Sr., was a complicated, real human being and not just a plaster saint to be worshipped throughout the years. Joe Hill’s existence broadens Frank’s character and affects those of Jamie Reagan (Will Estes), Danny, and the other family members. Thanks to Joe, everyone has to adjust their plans and behavior, and Joe must recalibrate himself to what it means to be part of a vast family that has formed a tight connection that doesn’t involve him.

Trying to acclimate oneself to a new family may be a common occurrence for viewers, but seeing Joe do it on “Blue Bloods” is quite a unique experience. Devotees of the show have been steeped in the Reagans and their rituals for quite some time. Without Joe, there’s no outsider point of view to deconstruct the family’s world — they just unquestionably are, without a single complaint or question from the observing audience.

His removal from the family was unceremonious

But all good things must come to an end, and Joe Hill’s time on “Blue Bloods” wraps up during Season 13, when the character is shipped off on an undercover mission. He isn’t heard from for the majority of the season, and while it’s intimated that he’ll always be a part of his new family when he goes, he is summarily forgotten about and very rarely discussed.

The moment couldn’t have come quickly enough for a certain group of “Blue Bloods” fans, some of whom named Joe among the “Blue Bloods” characters they can’t stand. There were fans who had called out Joe’s existence as a clear attempt at livening up a show that’s slid beyond its expiration point and felt that the seemingly-perfect Joe Sr. siring a child he never knew about a bridge too far. Some found his behavior annoying, even obnoxious.

And yet it’s hard to deny that there’s an enormous hole in the Reagan family with Joe Hill gone, and that his being shunted off to the hinterlands of parts unknown weakens the show’s overall reliance on family camaraderie. It’s an unceremonious gesture, and he deserves better.

As Blue Bloods comes to an end, we should really find out where Joe is

“Blue Bloods” will soon close up shop for good, with its final order of episodes set to finish airing during 2025. Undoubtedly, the show will find a way to conclude the stories of everyone, from Danny to Frank to Jamie Reagan, with aplomb. But if they don’t manage to bring Joe Hill back, they’ll be doing a disservice to the story they spent seasons telling about him and the Reagans’ message of cheerful togetherness.

Several family members have maintained long absences from the central flock before returning. Nicky Reagan-Boyle, for instance, disappeared from the show’s cast while Sami Gayle appeared on Broadway. So bringing Joe back to the show wouldn’t be a huge leap of faith — just another accepting action by a large family that brings a fresh meaning to the term “closely knit.”

Joe may not have been a perfect character, but his unique point of view makes him a missing piece that desperately needs to be slipped back into the Reagan family jigsaw puzzle. And bringing him back would be a gesture of warmth worthy of any of their Sunday night banquets.