This year marks the 20th anniversary of "The Fifth Element," French visionary Luc Besson's whirligig sci-fi epic about a cab driver (Bruce Willis) who befriends and falls in love with a space deity (Milla Jovovich) and ends up saving the galaxy and defeating a truly over-the-top baddie (Gary Oldman, naturally). It was a movie that seemingly came out of nowhere but was instantly embraced, if not widely than by a certain type of filmgoer that responded to its unusual and enchanting blend of comic book aesthetics, broad humor, thrilling action set pieces, and colorful characters. Two decades in, it's hard not to think of it as a lovably goofy, ahead-of-its-time masterpiece.

But the question remains: Why hasn't there ever been a proper sequel to the film?

The legend goes that Luc Besson started working on what would end up being "The Fifth Element" back when he was 15. By the time he had finished making "Atlantis," his gorgeous and elliptical documentary about oceans, his script had ballooned to 400 pages. While Besson developed the visual look of the film, production halted in 1992. Besson went on to make "Leon: The Professional" in the interim and following the release of that film, he worked to streamline the ungainly sci-fi project to something more manageable (and attractive for big movie stars). Obviously, he pared down the script and even scored Willis, who Besson had courted during the first iteration of the movie, to star. But what became of all that additional material?When Besson made the press rounds for "The Fifth Element," he casually mentioned a sequel or follow-up. The movie that the filmmaker had just completed was the first half of that massive script; the sequel would be the second half. Somewhere along the way it even got a name: "Mr. Shadow" (named after the malevolent force that threatened all mankind in "The Fifth Element").

In 1998, during the nascent days of the Internet rumor mill, it was reported that Bruce Willis had signed on for the follow-up and Mira Sorvino was also interested in a role. (Sorvino wound up in his 2001 martial arts thriller "Kiss of the Dragon," which Besson co-wrote and produced.) For his part, Besson was hard at work on his follow up (with "Fifth Element" co-star and then-wife Milla Jovovich). In a 2011 interview with Moviefone, Besson said he had no interest in doing a sequel and in a Reddit AMA in 2013 he said that any talk of a sequel was just a "rumor."

I talked to him that same year about a potential "Fifth Element" follow-up and he told me: "'The Fifth Element' ... I was a little bit frustrated because I made the film right before all the new effects arrived. So when I did the film it was all blue screen, six hours, dots on the wall, takes forever to do one shot. Now, basically, you put the camera on your shoulder and then you run and then you add a couple of dinosaurs and spaceships. And I was so frustrated because it was not so easy at the time. So I always think to myself that I would avenge one day and use all the new tools to do a sci-fi film for sure."

When I pressed him as to whether this sci-fi film would have any direct connection to "The Fifth Element," he demurred: "I don't know if it would be directly connected but it would be the same area and the same genre. So for me it would be connected even if the stories had nothing to do with each other." (Also worth noting: Besson and the movie's star, Milla Jovovich, divorced in 1999.)

Which brings us to Besson's approach to sequels, which can be a little tricky to understand. The only true sequels the filmmaker has directed himself involved a trilogy of animated features he made in France that were nominally distributed stateside. Otherwise, he has only written sequels (to mid-sized hits, like "Taken" and "The Transporter"). For years, he worked on a proper follow-up to "Leon: The Professional" and he said that none of the scripts were good enough. But when "Columbiana" (an assassin thriller he made with Zoe Saldana) was coming out, Besson spoke openly about it being a slightly modified version of the "Leon" sequel he had been working on, which at one point was titled "Mathilda." So it might seem like we never got the sequel to "Leon: The Professional," we did ... kind of ... you just have to look through the lens of Luc.Which brings us to "Valerian and the City of a Thousand Planets," Besson's next grandiose sci-fi extravaganza, scheduled to open later this summer. If you watch the trailer for the film, you'll notice key touchstones, like the exaggerated color palette, wacky alien species, and off-kilter comedic elements. The fact that there isn't a flying taxi in the trailer is a miracle. (Also, there probably is one, you just have to look hard enough.)

Unlike "The Fifth Element," which was merely inspired by French comic books, "Valerian" is actually based off of one. This is that follow-up that Besson was hinting about in those Reddit AMAs and the film he was talking about with me. What I mean to say is that maybe the "Fifth Element" sequel is actually happening right now and being released as "Valerian and the City of a Thousand Planets." Even if it doesn't have a direct connection, it's sort of that spiritual successor Besson mentioned. There's certain strands of the same DNA there.

So, even if we never really-for-real got "Mr. Shadow" (or whatever it might have been called), at least we get this. And, judging by the trailers, it's going to be awesome.