• Actor LL Cool J plays NCIS Special Agent Sam Hanna in 'NCIS: LA'

Actor LL Cool J plays NCIS Special Agent Sam Hanna in 'NCIS: LA' (Photo : REUTERS/Mario Anzuoni)

Fans should expect more drama when "NCIS: LA" returns on Sept. 21 for its seventh season as Callen eventually learns the truth about his father.

"NCIS: LA" season 6 final season saw Hetty lying to Callen concerning the details of his father's death. However, there should be a solution when the show returns three months after season 6 episode finale.

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In season 7, agent Callen will go rogue as he focuses on a secret project to look for his father, CBC reported. In his mission, Callen keeps both Sam Hanna (LL Cool J) and the whole team out of picture.

The first episode will focus on Callen's quest to uncover what happened to his father after meeting someone from his past. Apparently, this mission will take its toll on the relationship between Callen and the team.

Executive producer Shane Brennan told TV Guide that Callen's frequent disappearances will make the team raise concerns about his mission and cause a conflict between Hetty and other team members. He added that although the team has developed a solid relationship out of the many years of working together, Callen's secrecy will affect their trust.

Brennan asserted, "He finds himself in a very difficult situation with Hetty and Sam, because he's not telling them what he's got himself caught up in."

The show conventionally establishes a foundation about what will come in future, and the tradition has a great effect throughout the season.

The biggest problem will be Hetty's opposition to Callen's quest to find his father, which will ultimately make the whole team to pursue Callen so that they stop his investigation. In a recently released trailer, Sam and Hetty threaten to shoot Callen.