VIDEO: Sneak Peek - Season Finale of CBS's NCIS: LA

On the next episode of CBS's NCIS: LA titled 'Descent,' 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.

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. Get a sneak peek below!