Battlestar Galactica: The Plan" is not a prequel to the recently concluded television series. It's not a sequel.

It's a — well, it's whatever you would call a movie whose narrative is concurrent with a narrative we've seen before. And tells the same story from a different perspective.

Directed by "Galactica" star Edward James Olmos, this new production — which is out on DVD and Blu-ray on Tuesday — recounts much of what we saw in the first season. Only this time it's from the perspective of the Cylons.

If you're not a "Galactica" fan, most of this will be incomprehensible to you. If you are a fan, you will be riveted.

If you're somehow completely unaware of "Battlestar Galactica," it's about a war between humans and the robotic Cylons. Created by man, they rebelled, there was a big war and — 40 years ago — the two went their separate ways in a fragile peace.

When the series opened, the Cylons returned and nuked the 12 planets occupied by humans. A few thousand escaped in a fleet led by the Battlestar Galactica.

"The Plan" shows us those events from the vantage point of the Cylons. Specifically, the Cylons who appear to be completely human.

If "Battlestar Galactica" is a bit of a geek show — and there's no denying that it is — there is a huge geek-out sequence early in "The Plan." We actually see the Cylon attack on the 12 Colonies.

We see the Cylon baseships operate in a way we've never seen them operate before. We see amazing special effects. We see planets we've never seen before — before and after they're nuked.

"Galactica" fans will know what I'm saying when I tell you it's unbelievably cool.

But, as real fans know, "Battlestar Galactica" was never really about all the special effects and space battles. It was about the characters and the drama. And, for five seasons, it was one of the best dramas of any kind on television.

"The Plan" mixes some footage from the series with a lot of new scenes. Again, the focus is on the Cylons — not just the new models who nearly destroyed humanity, but the "Final Five" from an older civilization who are not even aware they are not human.

Because, of course, as we learned in the course of the series, this has all happened before.

(And, no, we're not talking about that cheesy 1970s series that inspired this "Battlestar Galactica.")

"The Plan" is not so much about big revelations of things we didn't know before. It's about filling in some gaps and making us better understand why the Cylons did what they did and how they changed their path.