Movies about vampires, werewolves, or vampires AND werewolves are great fun to write about because no matter how eloquently you describe the plot, it is always going to sound stupid.

In “Underworld,” the vampires and werewolves are two warring factions, living in the modern world but keeping their existence hidden from humans. Their dispute is centuries old, and it deals with some experimentation to combine the two species, as well as an old forbidden cross-species love affair.

See what I mean?

It’s the sort of film that’s far more fun to talk about that it is to watch. It doesn’t rise to the level of hootingly bad camp; it’s too turgid and serious for that, with overwrought dialogue like this bit from the opening narration: “The lycan horde scattered in the wind in a single evening of flame and retribution.” Gotta love it.

Ages ago, there was a big war between the vampires and the werewolves (called lycans, thank you very much) in which head vamp Viktor (Bill Nighy) allegedly destroyed the head lycan, Lucian. But Viktor is gone now — we don’t know why, and we don’t know why the war happened in the first place — and leading the blood-suckers now is a guy named Kraven (Shane Brolly), which is a play on the word “craven,” which means “cowardly,” so you know where this is going.

Viktor’s main supporter is Selene (Kate Beckinsale), and she pines for him and doesn’t like Kraven. Meanwhile, the wolves seem to be chasing a specific human named Michael (Scott Speedman), which puzzles and worries the vamps, who assume nothing good can come of the lycans targeting a human for anything other than food purposes.

I had no idea what was happening for much of the film, or why. The vamps and wolves mostly stay away from each other; it is only in the end that a full-on battle takes place. Most of the questions are answered eventually — what started the war, why Michael’s being chased, etc. — but I question the wisdom in keeping an audience in the dark for so long while simultaneously giving them so few characters to be interested in.

The Underworld series:

“Underworld” (2003) C-
“Underworld: Evolution” (2006) C-
“Underworld: Rise of the Lycans” (2009) C-
“Underworld: Awakening” (2012)
“Underworld: Blood Wars” (2017) C

It’s disappointing to see vampires and werewolves misused in such a manner. They have almost zero contact with the human world — in fact, what alarms the vamps most about the wolves’ seeking Michael is that they’re chasing him in broad daylight — and consequently the film feels disconnected from reality, even more than a movie about mythological creatures needs to be. We don’t know what city it all happens in; it might as well be a fantasy world, or an ancient city, or another planet.

The scenes of people transforming into werewolves (they can do this at will, independently of the moon cycle) are extremely cool, and there’s a dark broodiness about the whole thing (directed by first-timer Len Wiseman and written by him and two other rookies) that could have worked if the story made more sense and if there were someone to root for. As it is, it’s just a lot of darkness and nonsense.

C- (1 hr., 57 min.; R, some harsh profanity, some strong violence.)