Ellie Bishop will celebrate her second full year at NCIS later this year. She has proved a valuable asset for Special Agent Gibbs and his team, but leaving her old job at the NSA has caused some strain between her and her husband who still works for the intelligence agency.

When "NCIS" returns later the month, Bishop (Emily Wickersham) will find her marriage "tested and challenged" and that conflict will play out for much the 13th season's first half.

"Bishop... has a tremendous arc coming up," executive producer Gary Glasberg told TV Fanatic. "Her husband remains with the NSA and she's with NCIS so that's going to take a huge toll on her and will manifest itself in a bunch of ways that will be significant all the way through the holidays and beyond."  

"NCIS" introduced more of Bishop's husband Jake Malloy (Jamie Bamber) last season when he struck up a surprising friendship with Gibbs (Mark Harmon), who needed his help tracking down a Russian assassin. Much of their relationship history still remains a mystery.

Bishop isn't the only NCIS member working on her personal relationships this season. McGee (Sean Murray) will continue to mature in his relationship with girlfriend Delilah (Margo Harshman). He'll so find himself in the power struggle between Gibbs and Tony Dinozzo (Michael Weatherly) in the aftermath of Gibbs' shooting.

"Gibbs and Tony are really going to feel some tension between the two of them," Glasberg said. "Gibbs is putting tremendous pressure on Tony. Having survived [his shooting], Gibbs really wants to know if this is what Tony wants. Does he want to be the leader? Does he want to be, in essence, to become Gibbs?"

"NCIS" will return on Tuesday, Sept. 22 at 8 p.m. on CBS.