Here is the official description for NCIS: Los Angeles season 6 episode 18, "Fighting Shadows" - airing March 23rd.
Season 6 Episode 18 "Fighting Shadows"
THE TEAM SEARCHES FOR THE PERSON BEHIND AN EXPLOSION THAT KILLED THREE UNDERCOVER FBI AGENTS
When three FBI agents are killed in an explosion following a successful undercover sting operation, the team searches for the person behind the attack. Meanwhile, Deeks and Kensi realize the team knows about their relationship, as Hetty pairs Kensi with Sam and Deeks with Callen during the investigation.
Chris O’Donnell (NCIS Special Agent G. Callen)
LL COOL J (NCIS Special Agent Sam Hanna)
Linda Hunt (Operations Manager Henrietta “Hetty” Lange)
Daniela Ruah (NCIS Special Agent Kensi Blye)
Eric Christian Olsen (LAPD Detective Marty Deeks)
Barrett Foa (Tech Operator Eric Beale)
Renée Felice Smith (NCIS Intelligence Analyst Nell Jones)
Miguel Ferrer (NCIS Assistant Director Owen Granger)
guest & recurring cast:
Alexandra Barreto (LAPD Detective Jacqueline Rivera)
Christina Cox (FBI Agent Allison Conway)
David Diaan (Vakeel Shah)
Aaron Ramzi (Dogan Malki)
Asante Jones (Navy First Lieutenant Winters)
Julien Ari (Naveed)
Mykel Shannon Jenkins (Seller)
Jake Matthews (FBI Agent Jalil Nasri)
JoJo Nwoko (Jonathan Bakhzari)