Endgame is the 1st and Season premiere episode of NCIS: Los Angeles Season 4 as well as the 73th episode of the entire NCIS: Los Angeles series.
In the aftermath of the events in San Voirs Part 2, OSP struggles to come to terms with Callen's public shooting of the Crimeleon but all is not what it seems.
The episode begins with a recap of what happened in the NCIS: Los Angeles Season 3 finale episodes, Sans Voir Part 1 and Part 2 and ends with NCIS Special Agent G. Callen being arrested by LAPD officers and placed in the back of their patrol car after he was filmed shooting Marcel Janvier or the Crimeleon dead.
- It's revealed that Sam knows Farsi.
- LL Cool J (Sam Hanna) reads the "Previously on NCIS: Los Angeles" line.
|G. Callen||Chris O'Donnell||NCIS Special Agent and the leader of the Office of Special Projects field team.|
|Kensi Blye||Daniela Ruah||NCIS Special Agent with the Office of Special Projects.|
|Marty Deeks||Eric Christian Olsen||A Detective with the Los Angeles Police Department and also the LAPD/NCIS liaison.|
|Eric Beale||Barrett Foa||Tech Operator with the Office of Special Projects.|
|Nell Jones||Renée Felice Smith||Tech Analyst for the Office of Special Projects.|
|Henrietta Lange||Linda Hunt||Operations Manager with the Office of Special Projects.|
|Sam Hanna||LL Cool J||A former Navy SEAL-turned-NCIS Special Agent with the Office of Special Projects.|
|Owen Granger||Miguel Ferrer||Assistant Director for NCIS.|
|Marcel Janvier||Christopher Lambert||A criminal known as the Crimeleon who is an arms dealer and an master identity thief.|
|Kelvin Atley||Cooper Thornton||Analyst with the NSA.|
|Naseem Vaziri||Alon Abutbul||VEVAK Agent (Iranian Intelligence).|
|Pete||Lovensky Jean-Baptiste||NCIS Special Agent.|
|NCIS Agent 2||Kim Swennen||NCIS Special Agent.|
|Hosein Khadem||Erick Avari||Former SAVAK Agent (Iranian Intelligence).|
|Female Teller||Candice Afia|
|Male Teller||Adrian Gonzalez|
|Male Bodyguard||A.J. Castro|
|Justin Atley||Daniel Okeefe|
|Homeland Security Agent||Mike Whaley|
|Iranian||Roman Mitichyan||Uncredited role.|