The fourth film in the "Twilight" series reveals a flash or two of real filmmaking (mostly in a suggestively grotesque birthing sequence), enough to save it from pure lousiness.

But a significant number of its 117 minutes do seem like hours, and whenever certain actors take the lead and set the pace of the dialogue, time itself begins to crawl backward and the breaking dawn begins to feel like yesterday's breaking dawn, or last Tuesday's.

How did this happen? Quite apart from the source material's morbidity — the Stephenie Meyer novel, a combined abstinence lecture and anti-abortion allegory, has been broken into two separate features, this year's and next year's — how did Bill Condon, the director with the most stylish and idiosyncratic resume of any to undertake a "Twilight" installment, deliver the dullest movie of the bunch?

And is there anything to do about Taylor Lautner? He's had four films now to improve, yet he's still coming off like a reedy-voiced pretender, doing his best, but…say what you will about Robert Pattinson (fwoopy-haired vampire Edward) or Kristen Stewart (Edward's squeeze, Bella), but Stewart is up around here, Pattinson a little below that, and Lautner (heartbroken werewolf Jacob) is down there somewhere.

So: Sex with a vampire. Finally. For three films now, the "Twilight" narrative has practically goaded the audience into having intercourse on behalf of the characters. (Bella is 18, and in "Breaking Dawn" she gets pregnant with demon child about 20 minutes after losing her virginity.) The smoldering and the we-can't-we-shouldn't sweet nothings have been going on between Bella and Edward, with a side order of Jacob, for what seems like centuries. Honeymooning on an isle off the Brazilian coast, bammo: Edward's demon seed starts its journey and eventually starts breaking Bella's bones from the inside. (Told you: morbid!) Once Bella is fighting for her life back home in Forks, Wash., the controversial pregnancy foments another round of species warfare between the vamps and the wolves.

"Twilight," the phenomenon, sells one thing above all else: the idea of sex with serious, immediate and clinically painful consequences. Of the "Twilight" pictures to date, this one works least well as a stand-alone product. Condon does strangely little to energize the various heart-to-hearts and the wedding-jitters montage scenes. The oversized wolves, the superfast-motion imagery and other "Twilight" effects flourishes look as cheesy as ever. Composer Carter Burwell, one of the best in the business, has been dragged down to a level of mediocre wallpaper music one wouldn't have thought possible.

But don't listen to me. I enjoyed the first two for what they were, and didn't much like the third one, which many considered the best. "Breaking Dawn — Part 1" sets up "Part 2." That should be enough from a business perspective. Those who are committed to this franchise are committed to this franchise.

"Twilight Saga: Breaking Dawn Part I"

Grade: One and a half stars out of five

Genres: Adventure, drama, fantasy, romance

Running Time: 117 minutes

MPAA Rating: PG-13