Jeri Ryan Jeri Ryan

NCIS is finally filling in a major missing puzzle piece about Gibbs' background.

The show has cast Jeri Ryan as Gibbs' (Mark Harmon) fourth ex-wife Rebecca, TVGuide.com has learned.

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Showrunner Gary Glasberg previously teased that the mystery redhead would be introduced in Season 12. "After 12 seasons there was still one ex-wife to cast opposite Gibbs and we found her in the beautiful and talented Jeri Ryan," he said in a statement. "We're all very excited to have Jeri join us for a storyline that's chock full of surprises."

Ryan will make her debut on the show in January.

Rebecca is the only ex of Gibbs' that viewers haven't yet met. His other ex-wives — all of whom are redheads — are Shannon (Darby Stanchfield), who was murdered along with the couple's 8-year-old daughter by a Mexican drug dealer; Diane (Melinda McGraw), who drained Gibbs' bank account before leaving him and is also the ex of Agent Fornell (Joe Spano); and Stephanie (Kathleen York), who also left him.

Ryan was previously a series regular on Star Trek: Voyager and Body of Proof.

Are you looking forward to meeting Rebecca?

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(Full disclosure: TVGuide.com is owned by CBS.)