When viewers last tuned in to "NCIS: Los Angeles," Hetty sent Kensi to Afghanistan to work on a top-secret mission with Granger, disrupting her relationship with Deeks. 

Showrunner Shane Brennan told TVLine that Kensi's assignment "came at the very, very worst possible time for her and Deeks." But at the same time, he said "it's been a lot of fun, and we've really enjoyed doing it."

The writers did not originally intend to send Kensi to abroad, but the showrunners needed to find a way around Daniela Ruah's maternity leave.

Despite Ruah's pregnancy, she will appear in every episode, according to Brennan. 

"If you noticed, she went to a cold climate where she needs to rug up!" Brennan told TVLine of Kensi's bulky clothing while on her mission in Afghanistan.  

He also said that Kensi's mission "has turned into a great arc for the second half of the season - the whole mystery of what she's doing there, who the 'White Ghost' is.... And it's been fabulous to team her up with Granger."

While he said her character on the show will not get pregnant, he hinted that "Densi" will experience a shock "that turns everything on its head...and impacts them in a very, very, very big way."

Until then, he said viewers can count on "a lot of fun episodes" that focus on the relationship between Callen (Chris O'Donnell) and Sam (LL Cool J), as well as an episode where Deeks (Eric Christian Olsen) goes undercover as a "fabulous" interior decorator names Sven. 

Eric's (Barrett Foa) past life also "pays a call on him" on or around episode 17. 

Cult film actor Danny Trejo ("Machete Kills") will also guest star during February sweeps as a man from Hetty's (Linda Hunt) past.  

"It's a big episode that takes everyone down to Mexico, where there's a lot of action as well as character stuff for Callen, Sam and Hetty," Brennan said.  

The next episode of "NCIS: LA" is titled "Allegiance." It will focus on the murder of a federal agent in L.A that is tied to Hawala, an ancient system of money transfer. The murder will reunite Kensi and Granger with the NCIS team in L.A to try to stop a possible terrorist attack. 

"NCIS" returns with "Allegiance" on Tues., Jan 14 at 8 p.m. on CBS.