‘Tracker’ Casts Jensen Ackles as Colter’s Brother Russell We’re meeting Russell Shaw this season, and the cast couldn’t be better.

Jensen Ackles has been cast as Colter Shaw’s estranged brother, played by Justin Hartley, in Tracker. (Fun fact: They both starred on Smallville, but at different times.) Hartley broke the news himself with a hilarious Instagram video featuring Ackles, and TV Insider has learned he’ll appear in the May 12 episode.

In “Off the Books,” Colter is forced to team up with his estranged brother, Russell, who enlists his help in tracking down an old military buddy who has gone missing after weeks of paranoid behavior. The investigation takes the brothers into a world of Special Forces missions, shady off-the-books programs, and conspiracy theories, all while they wrestle with their family’s past. Check out a photo from the episode above.

At the time of the premiere, Colter has received a series of text messages that he has ignored: “Come on, Colter. Call me back. We need to talk.” “Don’t ignore me, Colter. There’s something you need to know…” “I’m not going anywhere. You need to hear what I have to say.” The episode ends with Colter returning to the cabin, where his mother has accompanied him to his father’s grave. He tells her about Russell’s calls and asks her if she knows anything about his brother or father that he should know. She tells him to block the number and ignore him. She’s asked him very little over the years, but all she wants is for him to leave it at that, for everyone’s sake.

The news of Ackles being cast as Colter’s brother comes shortly after Hartley revealed that Melissa Roxburgh will play his sister, Dory, as an adult. She will appear in the May 5 episode, “Beyond the Campus Walls.” In that episode, when a graduate student goes missing after a house party, his friends and family believe he succumbed to the pressures of a research grant. But after consulting with his sister, Dr. Dory Shaw, a professor at the school, Colter discovers a series of sensitive photos and text messages that lead him to uncover a dangerous — and deadly — plot on campus.

What do you think of the casting of Jensen Ackles as Colter’s brother? Let us know in the comments below.