DVD Talk's Jeffrey Robinson felt that Billie and Christy were the strongest parts of the season, and Sheldon Wiebe of the entertainment website Eclipsemagazine.com regarded the characters as re-establishing a "dark undercurrent" reminiscent of the show's first and second seasons.
Jeffrey Robinson and Sheldon Wiebe both found Billie and Christy to be strong points in the show, with Robinson emphasizing their impact on the season's quality and Wiebe highlighting their contribution to the show's darker tone.