The Fighting McLains (S06E01)

Title: The Fighting McLains Plot: Belle Starr McClain, an undercover agent, is on a mission to expose Jack Garrett. When he discovers her true identity, he murders her. In response, Walker sends an operative to secretly record Garrett confessing, but just as he’s about to strike, an unexpected assailant appears, aiming to kill Garrett. It’s revealed to be J.W. McClain, Belle's brother and a disciplined marine with a rebellious streak. Before her death, Belle had sent J.W. crucial evidence against Garrett, which he refuses to hand over. Meanwhile, Garrett captures Walker's operative, killing him after learning about J.W.'s evidence. As J.W. is escorted to safety by Marine Staff Sergeant Parrish, Belle's siblings attempt to confront Garrett but are overpowered, leading to Walker’s capture of the sister. Eventually, J.W. and his allies devise a plan to take down Garrett.