In two sneak preview clips from tonight's all-new NCIS episode, we see Gibbs and Fornell on the hunt for an elusive person of interest ... who they both happened to be married to at separate points in their lives.

Gibbs teams up with his FBI Agent counterpart (recurring guest star Joe Spano) on a joint NCIS/FBI investigation after Fornell becomes the target of a shooting, but they face an unexpected twist in the case.

Their mutual ex-wife, Diane Sterling (guest star Melinda McGraw), gets involved ... and clearly rattles both Tony and McGee. Speaking of which, she reportedly stays overnight at McGee’s, fueling office gossip.

We'll have to wait and see what actually happens with that situation, but in the sneak peeks below, we see Gibbs and Fornell track down their joint ex, and learn that Diane has been using dueling aliases.

Watch the two scenes from "Devil's Trifecta" and comment below!

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