The plague zombies in 28 Days Later act--and more importantly, are shot--in a manner that's startling and intense. They're much less like Romero's zombies than they're like the maniacs of La Invasión de los Zombies atómicos (aka City of the Walking Dead) or, more to the point, the more active of the vampires in Matheson's I am Legend, to which 28 Days Later writer Alex Garland owes a considerable debt. Garland makes his athletic zombies particularly nasty by the way in which they become infected; it's a disease carried by contact with blood, so that a perfectly normal person who gets blood in, say, his eye, will become a maniacal zombie within the space of half a minute. Boyle doubles the effect by the staggered, strobe-shot way he lenses the zombie assaults, not allowing our eyes enough time to adjust to the images he's firing at us. It creates a sense of immediacy and unease that create pockets of extreme tension within the effectively staged landscape of a strangely beautiful postapocalyptic Britain.

Which makes it kind of a shame when the movie makes a right turn into territory already treaded by Romero in Day of the Dead (and, in another way, by Boyle himself in Shallow Grave). It's not a bad narrative choice, I suppose, though the presence of the "radically" different alternate ending on the DVD indicates that Garland and Boyle weren't entirely positive they wanted the movie to go in the direction it did. Perhaps the movie couldn't or shouldn't have sustained a draining atmosphere of claustrophobic horror from beginning to end. However, even if the actors are up to the social commentary that characterizes the end of the movie, it's a distinct letdown after the horrifying vision that formed the first half.