Sullivan’s Crossing newcomer Marcus Rosner knows he has his work cut out for him after that secret husband twist — but could Liam actually be a threat to Maggie and Cal?
“Liam has a very complicated backstory and he’s a ghost from Maggie’s past. When the whole story is told, people will largely understand that this is a very relatable thing to have in one’s life,” Rosner exclusively told Us Weekly. “It is a very necessary thing to work through in order to get to your ultimate love story.”
Rosner reflected on the struggle of coming between a fan-favorite couple.
“It’s pretty hard to introduce a character in season 4 of a TV show that is about two people falling in love. Will people be rooting for Liam? I think the most I hope for Liam is for people to understand him,” he noted. “I hope people understand the past that he and Maggie shared together and how love is messy and there’s these different chapters that exist in one’s life.”
Season 3 of the hit series, which started streaming on Netflix in August 2025, initially hinted at Maggie’s (Morgan Kohan) ex when she mentioned Liam as a summer fling. He ultimately showed up ahead of season 4 — with Maggie’s boyfriend, Cal (Chad Michael Murray), finding out that she was actually married to Liam.
Rosner has had a significant presence in season 4 of the hit CW show — and the actor weighed in on how long Liam could stick around, adding, “It is to be decided if Liam will stick around. I would be open to it.”
Looking ahead, Rosner teased what is still to come for his character.
“We’re building toward some moments that will really test the audience — hopefully in a good way,” he noted. “Keeping in mind all the things we’re seeing with complexity of life and relationships, I think that if fans are scared that they will be dissatisfied … they need not have that concern.”
Rosner added: “This is really about Maggie’s journey and I think that at the conclusion of this season, her love story will really become crystallized in a way that perhaps it wasn’t previously.”
Despite feeling confident in the destination of the show, Rosner recalled how “terrifying” it was to be the new person on set, saying, “This is a TV show largely about two people falling in love and I try to get in the middle of Morgan and Chad Michael Murray — who was literally in high school lockers of all the girls. I knew it was daunting but I really believed in the character and I really like the character.”
Rosner said he initially felt “quite intimidated.” But he enjoyed getting to take on the surprise role after his extensive experience playing the lead love interest in a variety of Hallmark movies.
“I don’t have any expectations that people are going to be nice just because I’m a nice guy. I totally grant them every right to react to the story that they love and that passion is super necessary,” he told Us. “That’s largely what I’m seeing. I’m seeing things on both sides and people are kind of fascinated, curious, interested in how it’s going to unfold. Then there are people who are rightfully defenders of Maggie and Cal. Going up against somebody like Chad Michael Murray doesn’t make it any easier either. I go into it with very open eyes and just really grateful to all the fans for their passion.”
Sullivan’s Crossing is currently streaming on Netflix. Season 4 airs Mondays on The CW at 8 p.m. ET.
