Chicago Med’s Louis Herthum talks playing Will and Jay’s father

Louis Herthum portrayed Pat Halstead, father to Will and Jay, on Chicago Med. Photo Credit: Courtesy of East 2 West Collective.
Louis Herthum portrayed Pat Halstead, father to Will and Jay, on Chicago Med. Photo Credit: Courtesy of East 2 West Collective. /

Louis Herthum portrayed Will and Jay Halstead’s father in Chicago Med season 2, and told us about the experience and his parenting role on Westworld.

Last season Chicago Med fans met Pat Halstead, the difficult but ailing father of Dr. Will Halstead (Nick Gehlfuss) and his brother Jay Halstead (Jesse Lee Soffer).

The man who brought Pat to life as he dealt with his health issues, and mended fences with Will, was actor Louis Herthum. It’s because of Louis’ excellent performance that audiences were able to embrace Pat, and root for a Halstead happy ending.

One Chicago Center caught up with Louis to talk about his Chicago Med guest spot, and how he was able to portray one of One Chicago’s many difficult parents.

He appeared in the Chicago Med season 2 episode “Generation Gap” when Will had to deal with his father being admitted to the hospital, and the health crisis forced the two to face their tense relationship. Pat finally told Will the words he’d waited to hear for years:

“I had a blast doing that,” Louis enthused when we asked him about his Chicago Med experience. “It was great. They’re such a great group of people. Everybody on that show is just so sweet and kind.”

The other thing that appealed to him about the role of Pat Halstead was the fact that he’s so far removed from who Louis is in real life, or even most of the characters that he gets offered.

“It’s nice to be a jerk. I play a lot of nice guys,” he added with a laugh. “And it’s always nice to have people going oh my God, what a jerk this guy is, and then sort of [have him] be redeemed by the realization.

“That was a little hard to do, because Nick is such a sweetheart and how could any man not be proud of a doctor like that? But he was just such a hardcore blue-collar guy; he was more proud of the kid that became the cop than the kid that became the doctor.”

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While we have yet to see Pat make a return appearance on Chicago Med (even though both Will and Jay could benefit from some fatherly wisdom this season!), Louis is doing some great work on HBO‘s Westworld as he plays Peter Abernathy, the father to Evan Rachel Wood’s Dolores.

He’s still a father, but an entirely different one—one that isn’t technically human, but he still brings a wonderful humanity to the role.

And as he explained, playing a character who has such an important place in another character’s life, whether it’s Pat Halstead or Peter Abernathy, requires a certain approach.

“You have to be extremely sensitive to how they’re going to react to you,” he told us. “Since you’re playing the father, you have to react to them in a way that’s going to make them feel some connection to you.”

If you want to learn more about his current work on Westworld, check out our interview with him about that series here. But we’ll be hoping that we see Louis Herthum on Chicago Med again in the future, if only to enjoy more of his excellent performance.

Next: One Chicago's best sibling relationships, ranked

For more with Louis Herthum, read our Westworld interview with him at You can watch him every Sunday in new Westworld season 2 episodes on HBO.