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Marcus Rosner plays a pivotal role on season 4 of Sullivan’s Crossing as Maggie’s secret husband, Liam.
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 (Rosner) to Lola (Amalia Williamson) as a summer fling she had met before finishing medical school. After a meet-cute while on a trip abroad, Maggie and Liam fell out of touch.
Liam was brought up again when Cal (Chad Michael Murray) found letters Maggie had written to Liam explaining why their relationship couldn’t work long-term because she wanted to prioritize her career.
The rest of the season focused on Maggie and Cal’s relationship. Despite them not being an official couple, they faced several challenges, including Cal reconnecting with his estranged father who was battling a terminal illness.
After Maggie supported Cal through the difficult reunion, they returned to Sullivan’s Crossing, where he asked her to move in with him. They started planning their future just as the season came to an end, which is when a guest who checked in earlier that day revealed himself to be Liam. He then shocked Cal by referring to himself as Maggie’s husband.
Season 4, which premiered on The CW on Monday, April 20, will feature flashbacks that offer more insight into Liam and Maggie’s romance before she moved to Canada. Keep scrolling for everything to know about Rosner:
What Did Marcus Rosner Star in Before ‘Sullivan’s Crossing’?
Marcus Rosner’s most notable roles include UnREAL, Arrow, Supernatural and Once Upon a Time. He has also been a very consistent presence in Hallmark movies such as Autumn In the Vineyard, Love on Harbor Island, Romance to the Rescue, Flipping for Christmas, Love on the Right Course and Falling Like Snowflakes.
What Has Marcus Rosner Shared About His Personal Life?
In December 2020, Rosner announced his engagement to longtime girlfriend Alison Kroeker. They got married one year later. In January 2026, the couple welcomed their first child.
What Did the Cast Know About Liam Before His ‘Sullivan’s Crossing’ Debut?
Morgan Kohan previously teased the surprise twist, telling Swoon in July 2025, “I remember hearing a little bit [about Liam early in season 3]. I didn’t know they were married. There started to be talk when we filmed the scene with Lola and having summer flings. I knew that he was going to be coming into it, but I didn’t really know when or in what capacity. That cliffhanger was so much fun for me to read as well.”
Kohan acknowledged that Maggie’s trepidation about getting serious with Cal could have come from her past with Liam, adding, “I feel like it came up so last minute that I didn’t really have time to think about it, but I think it definitely would. It makes a lot more sense, for sure, for her to be more hesitant.”
The actress noted that she was just as in the dark about Liam’s role in season 4 as the audience.
“At the same time, I still don’t know the history, so who knows when we get to find out a bit more of that information, what he really means that he’s her husband and all that kind of stuff,” she continued. “I mean, there’s gonna have to be a few conversations had [between Maggie and Cal]. It’s going to be a trust thing to have to build up again because that is a pretty big thing to leave out.”
Sullivan’s Crossing took a surprising turn when Cal met Maggie’s secret husband — but who exactly is Liam? 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 (Marcus Rosner) to Lola (Amalia Williamson) as a summer fling she had […]
Could Liam Break Up Cal and Maggie on ‘Sullivan’s Crossing’?
Showrunner Roma Roth teased what the newcomer’s arrival meant for Maggie and Cal.
“There’s never a dull moment at Sullivan’s Crossing,” Roth told Collider in July 2025. “A romance drama series needs to have push and pull between your characters … we’re going to have a pretty big shoe drop at the end of the season that we’ll get to see play out in season 4.”
Roth said she wanted season 3 to reflect the theme of “second chances,” sharing, “These characters have been through a lot over two seasons. We wanted to give them an opportunity to explore love. I think that’s what we actually even called one of the scripts.”
Roth concluded: “Because we’re dealing with a lot of emotional issues we wanted to have some lightness and levity this season, by giving people a reprieve and having them have some hope and positivity in their lives. Continuing the journey from the head to the heart — with emotion and drama and a few surprises.”
How Has Marcus Rosner Transitioned From Acting?
In addition to being in front of the camera, Marcus Rosner has directed and written for projects as well.
“I’ve been fortunate to have a really privileged career both in front of the camera and as a producer, but in many ways it feels like all of that has been building toward stepping into the director’s chair,” he told The Northern Arizona Times in April 2026. “Acting is still my favorite part of the process, those moments between action and cut, but directing offers a different kind of creative fulfillment. Having that level of control keeps you engaged and creatively stimulated throughout the entire day, and that’s something I’ve found myself really craving.”
He added: “My background has been incredibly valuable in that transition. Acting gave me a deep understanding of performance, while producing taught me how films actually come together. Together, those experiences made stepping into writing and directing feel grounded and intentional. I have a clearer sense of what’s achievable, what’s interesting, and how to shape a visual and tonal language that feels specific to me.”
