Light spoilers ahead for the January 15 episode of Chicago Med on NBC.
The three shows of One Chicago are connected by one network, one night, and in one particular case circa the 2019-2020 TV season, one family. Yes, Chicago P.D.'s Jay Halstead and Chicago Med's Will Halstead are brothers, and they're the strongest family tie between One Chicago series since the Dawson sibs departed. Yet I've always had one big question about the Halstead bros, and it has burned all the hotter as the seasons passed: why don't they look anything alike? Now, I have my answer thanks to Med.
First, though, I feel I should explain why this question has distracted me. Other than having somewhat similar complexions and both being tall-ish, Jay and Will Halstead look different enough that I've always wondered if the casting team at Med kept Jesse Lee Soffer in mind at all when it came to casting Nick Gehlfuss as Jay's older brother.
With the two shows only occasionally crossing over, it wasn't going to really matter if they didn't look like blood brothers. And I will admit that I have two brothers, and the three of us don't look all that related unless you know to look for a resemblance. But still, I wondered about Will and Jay, and I'm grateful that Med gave me an explanation.
In the latest episode of Chicago Med, Will had helped deliver a baby, and he was in the room with the blonde mother and brunette father as they puzzled over how their newborn daughter was a redhead. Although there would later prove to be a complicated reason for the ginger baby girl, Will grinned and explained why it was perfectly possible:
As the only ginger in my family, I can tell you the redheaded gene is recessive, so it's possible it just hasn't expressed until now.
Well-played, Chicago Med. Well-played.
Now, did I know that the redheaded gene is recessive? Yes. Did I immediately take Will smiling and sharing that fact on Chicago Med as a way of showing Will has been asked this question many times and as a way of getting fans like myself to stop joking about the lack of resemblance? Also yes. In fact, back when this seemed to be a straightforward case, I felt like Med had successfully quashed my wild theories about an eventual reveal that Will had been switched at birth.
Neither brother especially looked like their dad, played by Westworld's Louis Herthum, but again, that red hair meant that Will was the outlier, and if I was going to speculate that one of the bros was switched at birth and/or had a different father, then it was going to have to be ginger Will. Yes, for part of the episode, I thought my outlandish scenarios of a soap opera twist for the Halsteads were all dead.
Then came the twist! The redheaded baby girl on Med was actually the product of an IVF switcheroo that saw two mothers implanted with the wrong embryo. Little newborn Maisie's red hair was a sign that the people who seemed to be her biological parents really weren't! I don't want to say this means that Will could be in for a rude awakening someday when he discovers it wasn't a recessive gene that turned him into the first and only ginger Halstead, but I will say that I probably won't stop joking about it.
And hey, if One Chicago goes the way of Law & Order: SVU and keeps running into more than two decades of cases, then maybe Med and/or P.D. will run out of story someday and need to throw in a twist about the Halsteads.
Are Will and Jay brothers related by blood, and Med's mention of the recessive gene was just a fun nod to the fact that Will is the redheaded man out in the family thanks to Nick Gehlfuss' hair? Absolutely, and I got a kick out of it. Did Med also leave the door open a teeny, tiny crack for fans to speculate for fun? Sure.
Of course, the Halsteads don't spend that much time together on-screen, since there hasn't been a repeat of the mess from last season when Will had to become a confidential informant to the feds, with Jay involved. They interacted throughout the "Infection" crossover, and Will appeared in the P.D. winter premiere while Jay was in the hospital from his gunshot wound.
The next big One Chicago crossover will be between P.D. and Fire, so there's no saying when the bros will reunite on screen again. Hopefully not because Jay gets shot again or a super weird Halstead love triangle! See what happens next with NBC's One Chicago Wednesdays, beginning at 8 p.m. ET with Med, continuing at 9 p.m. ET with Fire, and closing at 10 p.m. ET with P.D.