Massi Fulam, center

“Descent” — Pictured: Aunjanue Ellis (Michelle Hanna/Quinn) and LL COOL J (Special Agent Sam Hanna) and Timothy V. Murphy (Isaak Sidorov) (second from the left). A nuclear explosion in the Pacific reignites the search for stolen nuclear weapons and prompts Hetty to shuffle the NCIS: LA partnerships, sending Callen and Kensi overseas and leaving Sam and Deeks teamed up state side, on the season finale of NCIS: LOS ANGELES, Tuesday, May 13. Photo: Richard Cartwright/CBS ©2013 CBS Broadcasting, Inc. All Rights Reserved.