I enjoyed the story, it kept me interested until the end, which I didn't really like. I will say the end felt rushed, there was enough material to make it a longer story.
Also, the main character Audrey was annoying. Didn't want to be a burden and planned to strike out on her own, but after being severely injured, refused to get badly need medical attention, so became even more of a burden. My pet peeve is when characters do really, really dumb things just to further the story line. And what are the odds that of the handful of very few people Audrey encounters that survive the initial disaster, three of them are scientists.... And that two of them can predict the timing of the events. Really? A good read, kudos to good writing, but lots of holes in the story