“Tracker” star Justin Hartley previews the case that haunts Colter and Jensen Ackles' return in season 2

Showrunner Elwood Reid and the "This Is Us" alum preview Reenie’s new professional journey and the return of both Shaw siblings.

Prepare to meet Colter Shaw’s "white whale."

During the first season of Tracker, which follows Colter Shaw (Justin Hartley) as he tracks down people and items for reward money, viewers saw the survivalist successfully close cases on a weekly basis. But in season 2, we’ll discover there’s one case he couldn’t crack. “We’re going to introduce that he’s human and not a superhero,” Justin Hartley tells Entertainment Weekly. “He’s hung up on the fact that he couldn’t figure it out, and it’s haunted him for years and years.”

A decade ago, Colter couldn’t find a missing girl, and on each anniversary of her disappearance, he still investigates the case (and harasses the guy who was his top suspect). “It is not the case of the week, but we bookend the episode with his ‘white whale’ of a case, the case that he can’t shake,” showrunner Elwood Reid says.

Related: Jensen Ackles to return for Tracker season 2: 'We got him,' says star Justin Hartley

Part of what draws Colter back to the case is his complex relationship with the abductee’s sister. “It’s based on grief and it’s a shared grief that they have,” Reid teases. “It’s another way to access Colter’s character emotionally.” After a decade, the sister is ready to move on, but Colter is not as ready to close that chapter.

While the premiere will set up this piece of Colter's past, viewers will have to wait a bit before getting answers about the secrets tied to Colter’s father and his childhood. At the start of the series, Colter was estranged from his brother Russell (Jensen Ackles), whom he believes killed their father, an eccentric man who taught Colter a lot about the outdoors. In the finale, Colter was shocked to learn that his sister Dory (Melissa Roxburgh) knows more about their father’s secrets than she led him to believe — though he keeps that shock to himself.

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“He’s an interesting cat, because he’s reactive to a point,” Hartley says of his character. “But for things like this he has the ability to sit on them until the time is right to strike.” That said, the actor promises Colter “will get to the bottom of it. He’ll find out who’s lying to him and he’ll find out why they’re lying to him.”

Related: This Is Us stars reveal the one scene they wish they could have done

“It percolates through the whole season,” Reid adds of the family drama. “It will really come into effect in the back half of the season.”

Ahead of Dory’s return, the Shaw brothers will reunite during a case involving UFOS. Reid teases that Russell shows up during the “highest point” in the case and the brothers’ reunion will include a key piece of their past. “There’s a secret that is revealed about their father that lands with both brothers,” Reid says. “There’s a memory you’ll see that Colter doesn’t have that his brother does about Colter and their father.” Now that the brothers are on better terms, they can actually compare notes and make some progress.

Hartley is excited to have his friend back as Russell. “Jensen came and he enhanced [the character] in every way. He augmented the character with the tiny touches he adds as an actor, so he made this his own in a big way,” Hartley says about his on-screen brother.

Related: Glen Powell jokes about getting confused for Justin Hartley: We'd make 'most boring body-swap movie'

While there are reunions in his personal life, Colter’s work life will look a little different in season 2: Robin Weigert is not returning to Tracker as Teddi, leaving Teddi's wife, Velma Bruin (Abby McEnany), to adjust to a new normal. “[Velma] and Teddy have separated.” Reid says, “Velma is struggling with what it means to be abandoned in some ways, and she’ll work her way through that emotion.”

Velma will be working out of Reenie Greene’s (Fiona Rene) new office instead of her home this season. “Both of these women, as they go through some stuff in their lives, are going to be able to lean on each other and get on each other’s nerves,” Reid says of the new pairing.

However, don’t expect Colter to spend much time at Reenie’s new office, because he’ll be on the road in his RV taking it one case at a time.

Tracker season 2 will premiere Sunday, Oct. 13, at 8 p.m. ET/PT, on CBS.

Read the original article on Entertainment Weekly.