The actors of NCIS: Los Angeles are hard at work on the second episode of the upcoming season 5.

While the title for the Jonathan Frakes directed episode title has not yet been released, it will see the return of Nate Getz (Peter Cambor).

He operational psychologist has been away from the Los Angeles office for the last few seasons. Nate occasionally turns up in unexpected locations (Afghanistan, an American Prison, Yemen) when his mission, tracking the Warriors of Islam, and another NCIS case happen to intersect. Cambor can be seen in the photo above working with Linda Hunt (Hetty)

The first episode will pickup where last season's "Descent" left off and will most likely focus on the rescue of the team and the search for the nuclear weapons. Episode 2 may get to delve into two highly anticipated plot lines - Callen's (Chris O'Donnell) and Deeks' (Eric Christian Olsen) pasts.

Eric Christian Olsen has already confirmed that this season viewers will see the LAPD Detective attempt to deal with his feelings for Kensi (Daniela Ruah) and have a chance to dip into his traumatic childhood when his mother makes an apperence. According to a tweet by executive producer John Peter Kousakis, the end of episode 2 will have an great Deeks/Kensi scene.

However, Kousakis has also stated that season 5 will also hold a big reveal in the Callen storyline.

"Many Callen secrets revealed in S5 #NCISLA #bestcrewinhollywood #secretsrevealed," Kousakis recently tweeted.

As a character with a complex and very mysterious back story, the new information regarding Callen could be almost anything. However, it would be interesting if the series finally brought the agent's father into the mix. Or they could answer the most obvious question, what does the "G" stand for?

Kousakis recently stated that if his Twitter account gets 500 followers, he will release information on the Callen reveal.

NCIS: LA returns to CBS on Sept. 24.

Tags: NCIS: LA NCIS: Los Angeles