After the October episode "Great White Open," fans returned to NCIS. That was Mark Harmon's final episode as Gibbs, though the character still appeared in the opening credits for the next 17 hours of content. NCIS averaged 10.9 million viewers per episode, trailing only Sunday and Thursday NFL primetime football.
But how long can it keep going? Throughout the 19th season, fans questioned whether it was worthwhile to stick with the show as Gary Cole's Alden Parker replaced Harmon's Gibbs
