Yellowstone's Marshals spinoff kept the deaths coming with another crucial character getting killed off in a shocking twist. During the Sunday, May 10, episode of the hit CBS series, Kayce (Luke Grimes) was still dealing with the aftermath of the attack on his ranch while navigating a new threat from his past. The episode picked up from the fallout of the prison bus crash as Kayce and Cal (Logan Marshall-Green) tracked down the last remaining inmate still on the loose.