Michael Emerson Says It Was 'Weird and Complicated' Being Wife Carrie Preston's Adversary on “Elsbeth” (Exclusive)

The couple opens up to PEOPLE about Emerson's guest-starring role on the hit CBS series — and working alongside each other on set

On Thursday, Dec. 12, Michael Emerson kicks off a recurring arc on Elsbeth, playing an unexpected adversary opposite his wife, Carrie Preston, who stars as the titular lawyer who continues to help the New York Police Department solve various murders on the latest Good Wife spinoff. 

Ahead of his debut as Judge Milton Crawford, the former Lost star, 70, and Preston, 57, spoke to PEOPLE about what to expect from his character and what it's like for the longtime married couple to go from loving spouses at home to sparring with each other on set. 

"It's interesting, weird and complicated," Emerson says of acting with Preston, particularly on the CBS procedural, which sees them at odds after Elsbeth meddles in a murder trial that Milton is presiding over. (See above for PEOPLE's exclusive preview of Emerson's debut episode, teasing the growing tension between Milton and Elsbeth.)

He adds, "It's like a two-layered acting day. You have to act like you don't know this person that you woke up with in the morning and treat them as if they are a fictional character, and as your adversary, not your spouse. So it's a lot going on. A lot is being tuned out while a lot is being opened up."

Related: How Carrie Preston Went from The Good Wife 'Side Dish' to Making Elsbeth 'a Full Meal' (Exclusive)

Unlike the series' past guest stars, who make one-episode appearances as various suspects and criminals, Emerson will have multiple episodes to get under Elsbeth's skin as Milton and "throw her off her game a little bit," Preston teases, adding that "it's really fun to have a Moriarty to my Sherlock, you know, that character that she can't catch, the thorn in her side."

For his part, Emerson says that his character's "an ongoing problem for Elsbeth," joking that when they "butt heads again, probably fairly soon," he'll be curious to see "who's going to win that collision."

Preston adds, "Playing those different dynamics is just fun."

The couple first met in 1994 before getting married in 1998. Now, 26 years into their marriage, Preston says, "We have a really good time together. We do the life thing very well together. We kind of balance each other out."

And although the two don't act on-screen together that often — Elsbeth marks the second notable time they shared scenes on one another's show after Preston had a recurring role on Person of Interest, which starred Emerson as a billionaire computer programmer — she says "we kind of even carried that same balance on set as well."

Related: Actress Carrie Preston Honors Husband Michael Emerson on 26th Wedding Anniversary: ‘My Partner in All Things Life’

Filming Emerson's arc also provided the two — who are usually both busy on their own shows, with Emerson most recently starring on Evil and appearing on season 1 of Fallout — with an unexpected chance to spend precious time together. 

"We did a scene together the other day, when we were shooting in Harlem, and we had a little break," Preston recalls of filming Elsbeth in Manhattan where the series is set. "The trailers were far away, so we just took a little stroll together, holding hands." 

She adds, "Normally that would be when I would call him or text him. But I didn't have to. He was just right there and that was nice. It was a beautiful little moment where I thought, 'Oh, this is so nice. I can actually just reach out and see you and hold your hand and we don't have to communicate some other way.' "

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Elsbeth airs Thursdays at 10 p.m. ET on CBS.