Later this season, NCIS will air a few episodes that introduce characters meant for next fall's spin-off (rumored to be titled NCIS: Legend; and starring Chris O'Donnell and LL Cool J).

According to series producer Shane Brennan, the unique installments will also shed light on an important aspect of Gibbs.

"There's a resolution to him, in a story that has spanned the entire series, from the very first episode all the way through,"  Brennan told Entertainment Weekly. "It really is a piece of information the audience is well aware of - part of his back story - and in the spin-off [episodes], he lays that to rest."

What are you hiding, Special Agent Leroy Jethro Gibbs?

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.