Harmon leaving NCIS

https://www.dailymail.co.uk/tvshowbiz/article-10082669/Mark-Harmon-exits-CBS-long-running-NCIS-18-seasons.html

When Jim Parsons no longer wanted to play Sheldon Cooper on The Big Bang Theory, it shut down at the end of the season. Will the same thing happen with NCIS ? I don't watch it as faithfully as I once did, and have never watched the many spin offs. I suppose they will keep going...