Ok ok, dear readers wrap your head around this weirdness. A few years back there was a Spanish film called "REC" which was in the genre of 'documentary horror.' Well, it was actually pretty good so they made a reboot for the american market. That reboot was called "Quarantine," and was amazingly a near shot by shot remake of "REC." Now there is both a "Quarantine 2" and a "REC2," but oddly the sequels diverge by an incredible amount. I've not seen "Quarantine 2," but from the trailers I gather it is set at an airport.
"REC2," however stays in the creepy apartment building of the first film. Now a special squad is sent in to recover a mysterious macguffin. They know that they are dealing with people infected by a mutated form of rabies.
Or do they? I won't give all the twists to the new film but I will say that the true cause of the madness that infects the apartment takes a big left turn from straight science and straight into the twilight zone.
The film is deeply exciting and disturbing. It has the good property that anyone can die at any time. Some of the deaths are pretty outrageous, such as death by bottle rocket to the mouth. There's not a lot of character in this film but there is lots, oodles of style, so overall it works fairly well.