The NCIS: Los Angeles team should watch their backs. After staying in the background for nearly year, the OSP mole is ready to come out guns blazing.

Ever since Tahir Khaled got the jump on Sam's family in "Revenged Deferred," Hetty (Linda Hunt) and Granger (Miguel Ferrer) have known that their house is not in order. Someone is feeding sensitive information to NCIS' enemies, and their crimes will light the fuse on an action-packed premiere.

"The first three episodes are like a freight train, and the mole is the catalyst for all of that," Eric Christian Olsen (Deeks) teased at San Diego Comic-Con.

The Under Secretary of the Navy will take over the case, putting Hetty's team under the microscope. As the powers that be comb through the employees of Los Angeles' Office of Special projects, Callen's (Chris O'Donnell) crew will be assigned to a case involving a Syrian terrorist. By episode 2, their investigation will propel them into the land of one of the world's most notorious conflicts.

"The state department intervenes and brings in a team to essentially go after everyone to take down the mole. Hetty's involved; she has to go to Washington. They take over headquarters," Olsen explained. "The mole gets very real, very quickly. They brought in a guest star who's playing this corporate drone who comes in to screw with our team, and our team is in Syria."

As the search for the traitor plays out, it will trigger a tumultuous change for Kensi (Daniela Ruah).

"My pregnancy has brought on reasons to hide the pregnancy, which has then inspired a very particular storyline this season - at least in the first half of it, that's all I know - where something very drastic happens to the whole team," Ruah told EnStars. "Kensi is affected by that a little bit more, and that poses obstacles and a big long trajectory for Kensi and Deeks."

Find out more when NCIS: LA returns to CBS on Oct. 2 at 8 p.m. ET.

Tags: NCIS: LA NCIS: Los Angeles television CBS