When NBC's The Blacklist returns, Red and Liz will be tasked with tracking down a mole while trying to unravel their own mysteries.

During "Anslo Garrick" and "Anslo Garrick - Part Two," the FBI realized that their security had been greatly compromised. Not only did Garrick (Ritchie Coster) and Fitch (Alan Alda) manage to storm the blacksite and obtain Red (James Spader) and Liz (Megan Boone), but the existence of the apple-eating man and his vast surveillance network was also revealed.

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While it's impossible to know who the traitor is for sure, fans should start taking a deeper look at each character. For instance, there are those characters that already seem duplicitous by nature, such as Agent Harold Cooper (Harry Lennix), who liaszes with various different agencies.

Lennix recently discussed his character's role in relationship to Red and Keen during an interview with Collider.

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"I think he sees Elizabeth and Red as knights and bishops in his big chess game that's going on, both with Red and perhaps with the director of the FBI. Reddington is not his only concern. He's juggling multiple situations, and he has to deal with all of those things," Lennix explained. "I think the character, Harold Cooper, is happy to sit behind the desk and enjoy 5 o'clock cocktails with the head of the NSA, as they discuss the situation of the day."

Could Cooper's vast web of connections make him an ideal candidate for a mole? Find out more when The Blacklist returns on Jan. 13 at 10 p.m. ET on NBC.