Deeks and Kensi are back on the job in NCIS: Los Angeles, but there are those who now believe they are no longer fit to be partners.

As "Reznikov, N," the series' 100 th episode, gets underway, the agents' higher-ups will begin to voice their concern that the two have grown too close. While Hetty (Linda Hunt) previously asked Nate (Peter Cambor) if he believed that Deeks (Eric Christian Olsen) and Kensi (Daniela Ruah) were becoming too involved to continue to work together, the pair's growing relationship will continue to raise eyebrows as season 5 continues.

"There is a scene in the fourth episode in, which is also the 100th episode, between Hetty and Granger (Miguel Ferrer), who are talking about Kensi and Deeks, where she says, 'Partnerships can be tricky,'" explained series creator Shane Brennan, according to Xfinity. "They are. And when the audience thinks things are back on an even keel, they're not."

While it has already been revealed that Deeks and Kensi will be split up as partners by midseason (Link), Hetty's concern regarding her entire team will penetrate the entire season. While Sam (LL Cool J) is convinced Deeks will be okay following the events of "Descent" and "Ascension," others, such as Callen (Chris O'Donnel) and Hetty, aren't so sure.

"Hetty is troubled by what has happened; she is concerned about the Deeks/Kensi relationship. I don't mean just in Episode 1 and 2," Brennan told Xfinity. "There are serious issues between those two characters and Hetty, apart from all the other issues she deals with, she cares deeply about these people. She has a fairly emotional journey this season."

According to TV Line, Hetty should be concerned about the partners.

"Their relationship goes to a new level, to a place that a lot of these shows don't go," Brennan teases.

NCIS: LA airs Tuesdays at 9 p.m. ET on CBS.

Tags: NCIS: LA NCIS: Los Angeles CBS television