A thousand episodes is an impressive feat for a franchise. ("By the way, I should point out that almost 500 of those are just us," NCIS star Sean Murray told TV Insider.) With the April 15 episode of NCIS, that's the milestone the franchise (which also includes Los Angeles, New Orleans, Hawai'i and Sydney, with two seasons remaining) will reach.

CBS has now revealed details and photos (which you can see below) for the episode, titled "A Thousand Yards" and featuring special appearances from LA's Daniela Ruah (who directed an episode of NCIS this season) and Hawai'i's Vanessa Lachey. Joe Spano is also returning as Fornell. According to the official description of the episode, "NCIS is attacked by a mysterious enemy from its past. Also, Vance attempts to mend his relationship with his estranged son [Spence D. Moore II] by explaining why, despite the ongoing dangers of his job, he chooses to stay at NCIS."

As for that aforementioned past foe, "we've heard this villain's name before," executive producer Steven D. Binder told us. "Like some of our better episodes, our people are risking their lives for each other. We're paying homage to the OG NCIS and the other shows."

Murray also shared that his "favorite thing about what we've done on the 1,000th episode is we've hidden little Easter eggs and things throughout the episode — and not just hidden. We're calling back to a lot of things, but it's kind of hard to describe. It's a great show for people who are tuning in for the first time or new fans. For people who have been with us for a long time, it's really special because, like I said, you're going to see Easter eggs of things. You're going to see things that reference old episodes, famous episodes that we've done. Little moments. We have characters coming back that we haven't seen in a really long time."