‘Tracker’: Melissa Roxburgh Previews ‘Complicated’ Relationship Between the Shaw Siblings Ahead of Guest Appearance (Exclusive)

Tracker is starting to introduce some more of Colter's family, and his sister is coming into the picture in the May 5 episode. Manifest star Melissa Roxburgh will portray Dr. Dory Shaw, and she spoke to PopCulture about Dory's relationship with Colter and much more. In the episode, "Beyond the Campus Walls," a grad student goes missing and Colter consults his sister, a professor at the school, to get more information. While it was initially thought he buckled under pressure, explicit photos and messages lead Colter on a dangerous and deadly conspiracy on campus.

Roxburgh admitted she thinks Tracker is "such a great show because it's so fun to watch Justin take down the bad guys every episode." But what's fun about the upcoming episode, Roxburgh shared, "You get to see a bit more into his personal life and his upbringing because I know in the first couple episodes, you got some backstory on all of that, but now we get to see it in real-time as adults, as the siblings are all coming back into the picture and we get to unravel that story more."

What also made the episode fun is the fact that Roxburgh and Justin Hartley are longtime friends, and working together is something the two have never done, "so it was honestly so fun," Roxburgh said. In addition, she expressed, "And then, honestly, I just love playing smart, intelligent women. So, her being a professor was super cool to play, and the dynamic that she has with her brother is so complicated, but that's always super interesting to dive into as well."

(Photo: Darko Sikman/CBS)

The episode will also further explore Colter's relationship with Dory, and Melissa Roxburgh stresses that he is "such a lone wolf in all aspects of his life that we see that with his sister as well as ... I think the strongest relationship that he has is with his mom. But in them coming together, Dory even mentions, /You never call me back. I never see you anymore.'"

"And I don't think he has a lot of ... He doesn't play a large role in her life," she revealed. "Because I don't know if they kept this in there or not, but in the script, she has a husband and some kids, and I don't think that he has a very strong relationship with any of them. So I think that she really wants him to be more a part of her life than he has been and hoping that he builds that bond with her more."

It seems like Colter and Dory's relationship is a complex one and going off of what fans know about the Shaw family already, it's not so surprising. What isn't complex, though, is Roxburgh's friendship with Justin Hartley, and it's what made acting alongside him that much easier. Even if they were supposed to act like they have a troubling relationship.

(Photo: Sergei Bachlakov/CBS)

"Yeah, it's funny, I've known him for so long, and working with him just brought out a whole different side of him, and it was so cool to see him in that capacity," Roxburgh said. "But as far as the two characters go, I think that because we have that history, it made the roles so much easier to just be there. Because these two people do know each other and they do have a history. And so, for Justin and I have a friendship just made it so much easier."

There's no telling how this episode will go down, but it will surely be an entertaining one. Don't miss Melissa Roxburgh guest star in the new episode of Tracker airing this Sunday, May 5 at 9 p.m. ET on CBS to see what happens.