Leroy Jethro Gibbs' ex-wife, Diane, and her other ex-husband, FBI Agent Tobias Fornell, will both make appearances when the top-rated CBS procedural returns from a one-week hiatus December 11.

In the episode, Gibbs teams up with Fornell on a joint NCIS/FBI investigation after Fornell becomes the target of a shooting, but they face an unexpected twist in the case when Diane gets involved.

Meanwhile, rumors run wild among the group after Diane stays overnight ... at McGee’s.

Should be entertaining to say the least. The upcoming episode's title, "Devil's Trifecta," is a takeoff on last season's "Devil's Triangle," which first introduced us to Melinda McGraw's character Diane.

Fornell spoke with Gibbs on the phone, but did not appear, on last night's NCIS episode (see link for TV Fanatic's review). Joe Spano's recurring character appeared on the Season 10 premiere in September.

Excited to see both Tobias and Diane back in two weeks?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.