Quarantine is a much better movie than its previews would lead you to believe. Previews make it look like people are trapped in an old building with zombies running amok in it. Maybe they came up from the sewers.
In fact it follows a reality TV reporter who is following an LA fire crew on calls. They go to a building when neighbors have reported screams coming from the apartment of an old lady. What follows is the outbreak of a savage, mind destroying disease where tenants and first responders find them sealed in with those already infected, by the CDC.
Like Cloverfield and Blair Witch, the film is shot from the single camera view of the reality reporter's camera man. Unlike those films the camera work is clean and does not distract the viewer. Watch the long shot when a call comes as the camera man has to follow the reporter down a hall, a flight of stairs and into a truck and realize it was all done in one take without cuts. The first 20 minutes of the film are the `reality show' walking around the fire house, talking to members of the fire crew and setting the stage by letting you meet the key players in the film. This is clearly the set up but it doesn't feel stilted. You don't feel like saying `get on with it" because you care about the characters. Carpenter, as the on air talent is likeable and believable, going from bubbly on air talent, to real reporter as things turn serious to scared human as she realizes just how deep in they are. And she takes the viewer with her.
Previews make this look like just another zombie film. There are certainly elements of that in Quarantine but for the genre it is so much better than much of the competition. They even have an explanation, scary in how reasonable it is, for what is happening. Is it "Sound of Music?" of course not. It is a horror film, but one in which the director has taken a lot of care to make the whole thing frighteningly possible.