An original, extremely well done thriller with talent readily available on both sides of the camera. Bullock pulls off the 'tough to care for/ eventually gal to cheer for' quite well, backed up by some multi- layered work from her supporting cast. Sarah Paulson does her usual knock out job in what basically amounts to a glorified cameo.
The scenes of violence and destruction caused by the effect of being exposed to the creatures ( wisely kept as abstract as possible ) allows the cast to create them for us through reactions to whatever it is they're witnessing.
All in all a jolly good****/***** popcorn flick.....I.J.S.