Mr. Emerick weaves an entertaining tale! Extinction Theory is a great read for anyone interested in zombie literature or apocalyptic scenarios. The concept of the fungus-induced zombie is great! I remember watching a show (possibly on Planet Earth) about the insect version of this fungus that exhibited similar traits. Mr. Emerick did a fantastic job of translating this into a plausible scenario!
The story elements were great. I enjoyed how the events unfolded--even if some of them were predictable! A lot of the zombie stories aren't going to break any molds, so it comes down to characters and plot. Extinction Theory does well on both accounts. The characters, while believable and genuine, are bare-bones: the personalities are filled in just enough to provide background but not enough to make the characters jump off the page.
The plot element that really fascinated me was the description of how the fungi flowered and shot out spores--very chilling and downright creepy. If you're familar with the real thing in insects, this is a pretty close approximation. It makes your skin crawl. The other plot elements were okay--nothing special or surprising, but good enough to make you want to finish the story.
I had to take off a couple of stars for the editing. The story is full of grammatical and spelling errors. Some of the problems are so basic that I don't understand how they escaped any type of editing--a once-over when the story was finished should have caught some of the problems. Punctuation, particular with dialogue, is a consistent problem. Lack of indents for new paragraphs is another--and a new paragraph should start when a new character speaks or takes action; these basic elements are absent.
If it were just a few mistakes, then it wouldn't be a problem--mistakes happen! The errors are throughout the work and can be distracting. If you find yourself stopping when you come upon a spelling or grammatical error (or if you're familar with basic writing rules), then you might want to prepare yourself before reading this work.
Overall, it's a great story with some really creepy, skin-crawling, elements but it's rife with grammar and spelling errors. If the formatting problems were resolved, this would be a five-star e-book!