Daybreakers starts out addressing some interesting ideas, but dumps them overboard for car chases and splattercore lite as it tries to cram three different movies into one.

Ten years after the outbreak of vampirism almost everyone has been converted, with just 5 percent of the population still human. But as their prey dies off, the vampires are starving.

Ethan Hawke plays Ed Dalton, a hematologist looking for a synthetic blood substitute that could save the vampires and stop human extinction. But his company’s real money comes from harvesting the few remaining humans, hunted by paramilitary squads, hooked up to machines, and bled until they die. Ed is a reluctant vampire, struggling with the morality of killing to live and troubled by the cold greed of his boss (the great Sam Neill) and the kicks his brother Frankie (Michael Dorman) gets being a manhunter.

When Ed protects a band of humans instead of turning them in, they turn to him for help. A lackluster love interest (Claudia Karvan), a former vampire who’s discovered the way back (Willem Dafoe), and an underground army briefly set the movie off toward a Children of Men-style uprising. As the blood supply becomes critical, vampires start to riot in coffee shops and the “subsiders” -- starving vampires who’ve turned animal -- are rounded up and exterminated.

The film is filled with striking images, and the world is deep and well developed. A subwalk connects the city’s buildings to protect vampires by day, makeup ads tout milk-white skin, and early on, a sign reading “Children Crossing 2-3 AM” brings home the world perfectly. Like Blade Runner, Daybreakers starts out using genre to address some interesting moral ideas, and there are obvious parallels to issues from dwindling resources to corporate misconduct and even war crimes. But this time the hybrid doesn’t work.

The cure for vampirism is silly, and the end game turns into a gory splatterfest, with beheadings stapled on as the characters fade into the background. And as a mechanic nicknamed Elvis (must we?), Willem Defoe is just plain bad. His occasional southern accent is goofy and distracting, and he seems to be a refugee from a different, campier movie, maybe Evil Dead 2 or Zombieland.

The special features are thin, just a commentary from the directors and the creature designer, a making-of featurette, the theatrical trailer, and a poster gallery.

It’s not a good sign when a review references so many other movies, but this time it’s appropriate. Daybreakers never finds its own footing as it shoehorns in bits and pieces of other films, and along the way it squanders a great premise, leaving its characters to drown in B-movie blood.

Daybreakers is available now from Lionsgate.