This film starts off like it is building up to a promising peak, but then resolves itself in an unsatisfying way. The characters seem like they are simply at the whim of a brief cold or flu, which involves no input from them. No, scratch that. That is what the audience feels like after about 3/4 of the way through it. The ending is very unsatisfying. The terror factor is replaced by a creep-out factor instead, but it is done so badly that you feel cheated. The first one, IMHO, is the best.