Pictured: Chris O'Donnell (Special Agent G. Callen). While Callen is undercover in the mail room of an office building to investigate an arms dealer, it is over taken by terrorists and Callen becomes a hostage. When the team arrives to help, they discover the entire building is wired with explosives, on NCIS: LOS ANGELES, Monday, Jan. 5 (10:00-11:00 PM, ET/PT) on the CBS Television Network. Photo: Michael Yarish/CBS ©2014 CBS Broadcasting, Inc. All Rights Reserved.