"Off the Grid" -- After Gibbs spots the brother of an "NCIS Most Wanted" suspect, he immediately assumes his former alias and goes undercover with their infamous anti-government militia. Also, Bishop and Reeves partner on an off-the-books investigation, on NCIS, Tuesday, Jan. 17 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured: Mark Harmon, Tobias Jelinek. Photo: Cliff Lipson/CBS é2016 CBS Broadcasting, Inc. All Rights Reserved