We've heard that Callen's father Garrison (Daniel J. Travanti) is going to come back in a big, unexpected way this season. His presence in Los Angeles will bring him and Callen a lot closer - and we mean that in a literal sense.
"[Callen and his father] become, at least temporarily, sort of Odd Couple roommates," showrunner Scott Gemmill tells TVGuide.com.
So, uh, how's that going to work? Let's just say that Callen will long for his lone wolf days. "Callen, who's spent his whole life looking for family, suddenly finds himself with family," Gemmill says. "[He's] used to his privacy in his space, and it takes some getting used to ... having a family member living with him."
(Full disclosure: TVGuide.com is owned by CBS.)