I Am Legend 

Yes, vampires. Matheson doesn’t apologize for reviving a hokey old monster: As he puts it neatly, “Before science caught up with the legend, the legend had swallowed science and everything.” But scriptwriters Mark Protosevich and Akiva Goldsman seem embarrassed by this conceit. They transform Neville’s shambling undead neighbors into super-fast albino mutants, turned rabid by a virus that was supposed to cure cancer but instead wiped out most of humanity. They also relocate the story from the ’burbs — where you might know your neighbors — to midtown Manhattan, where we can get a hundred-million-dollar view of the devastation left by a pandemic. From his shabby-chic apartment in Washington Square, Neville (Will Smith) fends off plague mutants who seem a lot like the infected in 28 Days Later, only with CGI used to make them scary instead of hyperactive camera work.

It’s hard to imagine someone better prepared to survive the apocalypse than Smith’s Neville. The whisky-swilling Everyman of Matheson’s novel has become a buff soldier and a brilliant scientist with a lab in his basement, where he can test potential vaccines on captured ghouls. For most of the film’s first hour, Smith shares the screen only with his winsome German shepherd, who accompanies him on hunting expeditions to a deer- and coyote-overrun Times Square. He moves among vistas of a desolate, sun-washed metropolis that are creepy — and beautiful. When he ventures into a dark building and sees something moving in the gloom, the moment evokes primal fears, like the discovery of the subterranean Morlocks in H.G. Wells’ The Time Machine.

For these sequences, I Am Legend is worth watching. New York City has been wrecked on film countless times in countless ways, but director Francis Lawrence (Constantine) offers a particularly haunting vision of the aftermath. Birds cry in the sylvan streets while we check out stray signs of the apocalypse, like a gas station posting nearly $7 per gallon.

Luckily for Smith, he’s the only driver alive. He turns in a convincingly twitchy performance as a man who lives in a state of repressed panic — understandably, since he’s spent the past three years interacting with no one but his dog, lab rats and the occasional mannequin.

But when Smith starts getting up close and personal with the monsters, the movie starts falling apart. Unlike Matheson, the scriptwriters don’t seem to have a clue about what they want to say with this end-of-the-world scenario, and they end up reaching for a dose of the same vague, feel-good spirituality that mars M. Night Shyamalan’s recent films. It’s a dark vision with a greeting-card final shot.

Stop here if you wish to remain completely ignorant of the ending. But I feel compelled to add a note of local interest. The film eventually reveals that one excellent place to wait out an apocalypse is . . . Bethel, Vermont. So when they start talking on CNN about the spread of Ebola or bird flu or vampirism, you know where to go. Just be sure to bring lots of garlic.