on July 30, 2013 :
This has power and emotion, but it needs editing. The story being told is at times just a bit too murky for a reader unfamiliar with your fictional setting to follow. While trusting the reader's power of inference is a good general guide, like all general guidelines it can be pushed too far or too hard.
No doubt you have some notes on the side about the specific developments that produced the apocalypse, the nature of the subsequent chaos, the identities of the various mutually hostile forces, and the development of the all-important symbiont. Some of the material in those notes could be constructively incorporated into the story proper, though there would arise the need to be careful about too much exposition.
Stylistically, you did okay, except for a few awkward constructions and some occasional overwriting. A good editor would point those aspects out to you, with suggestions for rephrasings.
Overall, well done: four stars. Drop me a note if you'd like some help with the rewrite.
(review of free book)