The CW’s “Walker, Texas Ranger” reboot, “Walker,” premieres Thursday, introducing “Supernatural” alum Jared Padalecki in the iconic title role of Cordell Walker, which was played by Chuck Norris on the original ’90s series. And at Padalecki’s side will be his real-life wife, Genevieve Padalecki, playing his onscreen wife.

Well, for the first few minutes she will be, as the mysterious death of Cordell’s spouse, Emily Walker, is what kicks off the drama’s plot. And just because Gen knew her character’s fate when she joined the project, doesn’t mean it was any easier for her and Jared to play out that tragedy for “Walker.”

“So when I first signed onto it, there was only the pilot that had been developed and the character, she had gone through a couple of different revisions and such to get where she is now,” Genevieve Padalecki, who previously worked with her now-husband on “Supernatural,...