"Descent" Episode 24 of Season 4
Pictured: Chris O'Donnell (Special Agent G. Callen). An explosion in the desert rekindles the search for stolen nuclear weapons and prompts Hetty to shuffle the NCIS: LA partnerships, sending Callen and Kensi overseas and Sam and Deeks teamed up stateside, on the fourth season finale of NCIS: LOS ANGELES, Tuesday, May 14 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Guest stars include Aunjanue Ellis as Michelle Hanna, Christopher Lambert as Marcel Janvier and Timothy V. Murphy as Isaak Sidorov. Photo: Sonja Flemming/CBS ©2013 CBS Broadcasting, Inc. All Rights Reserved.