The NCIS team in Los Angeles are about to face fatal trouble. In the upcoming episode of "NCIS: Los Angeles" season 6 titled "Expiration Date," Callen (Chris O'Donnell) and Sam (LL Cool J) are given the important task of apprehending a CIA spy. However, Sam gets shot, which is why the entire team needs to enlist the help of Thapa (Ernie Reyes, Jr.). 

Fans of the show will remember Thapa from episode 10 of the fifth season titled "The Frozen Lake." He is known to be an amazing Nepali fighter who knows what to do to help them find the shooter. Thapa is one of the practitioners of the "sayoc" style of martial arts, which will also be featured in the upcoming episode. 

Also in this episode, Kenzie (Daniela Ruah) and Deeks (Eric Christian Olsen) get embroiled in their first official argument as a couple after being together since the show's Christmas episode. In spite of the tense vibe of the upcoming episode after Sam gets hurt, Kenzie and Deeks provide the much needed comic relief for the crime procedural series. 

The official synopsis for the episode reads: 

"When Callen and Sam are tasked with apprehending a spy contracted by the CIA, Sam is shot and the team enlists the help of Thapa, the elite Nepali soldier from their past, to help to find the shooter. Also, Kensi and Deeks have their first official argument." 

Aside from Reyes, other guest stars to be featured in the episode includes Ella Desai as the spy named Parminder Nagra, Michael Gaston as CIA Agent Doug Emmerich, Barry Livingston as Chief Surgeon John Bates, as well as Jennifer Del Rosario who will portray the role of Nurse Maria Ramos. 

"NCIS: LA" season 6 episode 16 airs on Monday, Feb. 23, on CBS.