"œDescent" Pictured (L-R): Aunjanue Ellis (Michelle Hanna) and Timothy V. Murphy (Isaak Sidorov). 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: Richard Cartwright/CBS ©2013 CBS Broadcasting, Inc. All Rights Reserved.