It can be argued whether or not the creatures in this film are zombies, but 28 Days Later is definitely everything a zombie movie should be. Apocalyptic, tense, scary, full of action, it had it all. While Raimi-style zombie films with tongue-in-cheek humor can be great, and Fulci-esque gore-fests have their place, a truly scary zombie film is a rare pleasure to see.
Directed by Danny Boyle of Trainspotting fame, 28 Days Later displayed Boyle's flair for disturbing imagery and edgy writing. Like the best zombie films, the conflict was not only between the humans and the zombies, but also among the humans themselves, creating depth and meaning that other films lack.
The film opens in an animal testing lab, where animal activists, unaware of the consequences, set free some animals infected with a virus called "Rage." The movie then cuts to 28 days later, when the main character, Jim (Cillian Murphy), wakes up from a coma in a hospital that appears to be abandoned. He soon discovers that the entire city seems to be empty, and he wanders around, trying to figure out what happened. He eventually meets up with other survivors, who tell him about the "Infected," the people who have caught the virus and whose only thought is to attack humans. The Infected aren't dead, they're people enraged beyond reason, who will attack as soon as they are aware of any people nearby. They aren't slow like classic zombies, but like zombies, they are mindless, and the virus can be transmitted through a bite or through the blood, making you one of them.
One of the things that I liked about this film was how Boyle managed to have his characters do things that you knew would lead to trouble, but it didn't seem like it was because the characters were being stupid. It's annoying sometimes to have to grant the director some leeway in the varying intelligence of his characters for the sake of the plot, and I didn't have to do that in this case. Just an example of how this horror film is a cut above the rest.