Marcus Rosner knew exactly what he was walking into when he joined Sullivan’s Crossing in Season 4. Introducing a mysterious new man into the orbit of Maggie and Cal — arguably one of television’s most beloved slow-burn couples right now — was always going to spark controversy among fans. But according to Rosner, Liam was never designed to simply be a villain standing in the way of true love. Instead, he represents something much messier, more emotional, and ultimately more human: unfinished history.

The actor, who made his debut on the hit CW drama as Maggie’s secret husband Liam, opened up about the shocking twist and the complicated role his character plays in Maggie’s emotional journey. While some viewers immediately viewed Liam as a threat to Maggie and Cal’s future, Rosner believes the situation is far more layered than a straightforward love triangle.

“Liam has a very complicated backstory and he’s a ghost from Maggie’s past,” Rosner explained in a recent interview. “When the whole story is told, people will largely understand that this is a very relatable thing to have in one’s life.”

That relatability is what seems to matter most to Rosner. He understands that audiences are deeply invested in Maggie and Cal’s romance, especially after three seasons of emotional build-up, longing glances, and near-misses. Walking into the middle of that dynamic — especially as the man Maggie secretly married years earlier — was never going to earn him instant fan support.

Still, Rosner isn’t asking viewers to abandon Team Cal. He simply hopes audiences remain open-minded enough to see Liam as more than an obstacle.

“It’s pretty hard to introduce a character in season 4 of a TV show that is about two people falling in love,” he admitted. “Will people be rooting for Liam? I think the most I hope for Liam is for people to understand him.”

That distinction feels important. Liam doesn’t appear to be written as a manipulative villain trying to steal Maggie away from Cal. Instead, his presence forces Maggie to confront unresolved parts of her life that she thought were long buried. Season 3 hinted at Liam only briefly, with Maggie referring to him as a summer romance from her past. But when he finally appeared in Season 4, the truth hit much harder than anyone expected: Maggie and Liam had actually been married.

That revelation instantly shifted the emotional stakes of the series.

Suddenly, Maggie’s relationship with Cal wasn’t simply about building a future together — it became about untangling a past she had never fully explained. And for Cal, discovering that the woman he loves was secretly still married understandably created cracks in their otherwise stable relationship.

Rosner believes that complexity is exactly what makes the storyline compelling.

“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,” he said.

That idea of love existing in chapters has become one of the defining themes of Sullivan’s Crossing. The series has always explored how relationships evolve over time and how people carry emotional baggage into new beginnings. Liam’s arrival simply externalizes those lingering emotions in a dramatic way.

What’s especially interesting is that Rosner himself seems genuinely sympathetic toward the audience’s hesitation. He knows exactly how beloved Cal and Maggie are. After all, Chad Michael Murray’s Cal has become one of the defining romantic leads on television, and Rosner openly joked about the intimidating nature of stepping into that territory.

“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,” Rosner laughed. “I knew it was daunting.”

It’s a refreshingly honest acknowledgment of the uphill battle Liam faces with viewers. Murray brings years of fan devotion with him, and Cal has been positioned as Maggie’s emotional safe haven from the very beginning. Introducing another man into the equation — especially a husband viewers didn’t know existed — was bound to create tension.

But Rosner says he believed strongly in the material and trusted that the writers had a larger emotional destination in mind.

“I really believed in the character and I really like the character,” he explained.

That confidence seems tied to what’s still coming later this season. According to Rosner, the show is building toward moments that will deeply challenge the audience emotionally, though not necessarily in the way viewers expect.

“We’re building toward some moments that will really test the audience — hopefully in a good way,” he teased. “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.”

That comment alone has sparked major speculation among fans online. Many viewers initially feared Liam’s arrival signaled a prolonged love triangle that could derail Maggie and Cal’s story entirely. But Rosner’s wording suggests the show may ultimately use Liam not to destroy Maggie’s future romance, but to clarify it.

“This is really about Maggie’s journey,” Rosner added. “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.”

That may be the biggest clue yet about where the season is heading.

Rather than presenting Liam as Maggie’s “better” option, Sullivan’s Crossing appears more interested in examining what unfinished emotional business can do to even the strongest relationships. Maggie can’t fully move forward with Cal until she confronts what happened with Liam — and why she kept it hidden for so long.

In many ways, Liam functions less like a rival and more like a mirror reflecting unresolved pain back at Maggie.

Rosner also spoke candidly about joining an already established cast and fanbase. Despite years of experience starring in Hallmark romances and other television projects, he admitted arriving on set was “terrifying.”

“I initially felt quite intimidated,” he said.

Still, his extensive background playing romantic leads may have actually helped him approach Liam with empathy rather than defensiveness. Instead of trying to “win” viewers over immediately, Rosner seems comfortable allowing audiences to wrestle with conflicting emotions about Liam.

“I don’t have any expectations that people are going to be nice just because I’m a nice guy,” he explained. “I totally grant them every right to react to the story that they love and that passion is super necessary.”

That understanding of fandom has likely helped soften the blow of stepping into such a divisive storyline. While some fans remain fiercely protective of Maggie and Cal, others have become increasingly intrigued by the emotional mystery surrounding Liam and Maggie’s past marriage.

Rosner says he’s already seeing passionate reactions from both sides.

“I’m seeing things on both sides and people are kind of fascinated, curious, interested in how it’s going to unfold,” he shared. “Then there are people who are rightfully defenders of Maggie and Cal.”

At the center of it all is the reality that Sullivan’s Crossing has always thrived on emotional honesty more than simple fairy-tale romance. Relationships on the show are rarely clean or uncomplicated. People make mistakes. They hide things. They carry regrets. Liam’s arrival simply forces Maggie to finally face hers.

And whether audiences end up loving Liam or not, Rosner seems perfectly content if viewers simply walk away understanding him.

Because sometimes the most interesting television characters aren’t the ones audiences root for immediately — they’re the ones who force everyone, including the protagonist, to confront uncomfortable truths.