1: After 21 years, NCIS fans are finally getting closure on the series' incomplete villain storyline. The 1000th episode delivers the long-awaited payoff.

2: Fans have been waiting for this moment since the show's inception. The resolution of the 21-year-old villain story is a major milestone for NCIS.

3: The 1000th episode brings the culmination of a decades-long mystery surrounding a notorious villain. NCIS fans are in for a thrilling conclusion.

4: The long-awaited resolution of the villain storyline is sure to have fans on the edge of their seats. NCIS hits a major milestone with its 1000th episode.

5: The 1000th episode of NCIS finally ties up loose ends from a storyline that has spanned over two decades. Fans can expect an epic conclusion.

6: NCIS celebrates its 1000th episode by giving fans the closure they have been waiting for. The long-held mystery surrounding the villain is finally revealed.

7: After 21 years, NCIS delivers a satisfying conclusion to a storyline that has kept fans guessing for decades. The 1000th episode is a game-changer.

8: Fans of NCIS finally have their questions answered in the show's milestone 1000th episode. The long-awaited resolution to the 21-year-old villain story is here.

9: With the 1000th episode, NCIS wraps up a storyline that has been years in the making. Fans can finally put the pieces together and find closure.