The movie "28 Days Later" was a very well done zombie movie. However, if you were to take out the opening about the Rage virus and just started us with the hero waking up in the hospital bed, not knowing what the hell happened to England and all the people, it would have changed the terror of the story all together to a new height. We would have been pitched into the unknown with him. However, with the audience having this virus insight, we knew what happened the minute the hero faced an empty hospital.
In "Night of the Living Dead," we had some hints of a meteor or hell running out of room, but we never really knew why the world was upturned. It's that cut off from information, not sure what's happening that is horrifying. Just remember on 9-11 when we didn't know if planes were safe, subways, buses, malls, or how big this entire hit on America would be.
A great zombie story needs a few elements:
1. Lack of help from the outside. We're on our own here!
2. Lack of information. No radios, TV, saviors.
3. Difficult logistics. Dwindling supplies, being trapped, being surrounded.
4. Difficulty amongst the uninfected. Sometimes your worst enemy might be in your own group--someone has to make the job of staying alive more difficult than it already is.
5. Questionable future. We should never know how this thing ends or if it ends or if anyone even survives--a zombie apocalypse is never neat and tidy.
It goes without saying that a zombie movie will have the consuming of human flesh by the undead, but some movies completely depend on the graphics of that truth to shock, but they tend to leave us rather numb. The story is not so much that the zombies eat us, but how we evade such an eventuality. What are their abilities? What are our odds? Can having human intelligence beat the very natural animal need to feed? Ultimately, are we outnumbered?
Many directors and writers have worked to bring alive the story of the zombie in such a way that we say, "that was a great zombie story," but I think most would have to agree that the truly best was Romero's "Night of the Living Dead" and what it had going for it (besides the elements described above) was timing. At the time that it came out, it was a new terror, a new enemy, and the enemy was us!
The theme for zombie stories always comes down to the basic, "ordinary people in extraordinary circumstances." We see this in times like 9-11 where people show their true colors under stress. The truth of the matter in such circumstances is that sometimes good people trying to help others will be killed and this is a circumstance you find in a lot of zombie films and books, the martyr (the teenagers in "Night of the Living Dead"). There is also the gun-happy scared man in most stories, the guy who is such a trigger finger and so paranoid, he is likely to hurt us all (the father in "Night of the Living Dead."). There is always the one person who is useless in an emergency situation and may end up weighing down the group due to injury or mental breakdown (Barbara in "Night of the Living Dead"). Lastly, you have the hero who is trying not to feel anything about the situation, but work like a machine to make it work, the natural born leader (the hero in "Night of the Living Dead") You might also need to contain within the story those who are expendable (the mother in "Night of the Living Dead") and those who are infected (the little girl in "Night of the Living Dead").
Zombie stories come and go, but what we always look for consistently is not what the zombies are up to, but how the humans are handling it. It is like facing our greatest fears, that those humans around us suddenly become psychopaths.