Parasite was a disturbingly engrossing (and just plain gross) read. Mira takes her time introducing the readers to Sally Mitchell. She has just woken up to a room full of bright lights and odd sounds. Those odd sounds are gasps of surprise and tears of joy. You see, Sally was declared brain dead following a major car accident and her family was just about to pull the plug. Only the thing of it is, Sally doesn't remember anything about the person she used to be - she's a clean slate, in fact, with no memories whatsoever. Fast forward six years and now she's just Sal. Sal who is forced to undergo therapy sessions with a doctor who's grin shows too much teeth. She lives with her parents and a sister who keep waiting for her to regain her memories. She has a job she loves working with animals at a local shelter. She has a caring boyfriend who loves her for who she is. She just wants to be. Though her body is older, she's only six years old, so everyone's over protection of her is somewhat understood. She's struggling to prove that she's achieved a lot - she's now able to read, take care of herself, maintain a job, and form healthy relationships - but they see her differently. She is different, so much so that, apart from her boyfriend Nathan, they can't help but think she's hiding something. That alone would make for an interesting story - an amnesiac looking to build a new life. But, this is the year 2027 and most of the world's population have had parasitic implants called Intestinal Bodyguards, which were developed by a corporation called SymboGen. A decade in the future, humanity thrives in the absence of sickness and disease.We owe our good health to a humble parasite - a genetically engineered tapeworm developed by the pioneering SymboGen Corporation. When implanted, the tapeworm protects us from illness, boosts our immune system - even secretes designer drugs. It's been successful beyond the scientists' wildest dreams. Now, years on, almost every human being has a SymboGen tapeworm living within them. Sal owes her life to SymboGen because without her parasite she would have died. Since she woke, she's been "under the care" of SymboGen. The bonus is that all of her medical care is paid for by them. The downside is that she is subjected to a number of tests twice-yearly including ongoing mental health therapy sessions.When people begin suffering and dying from what's being called the "sleeping sickness" and Sal and her boyfriend, Nathan, who is a parasite-free parasitologist, are caught in the middle of it all they work to try to find out the cause and how to stop it. Sal's father, an Army Colonel and director of the local medical research center, is looking for answers as well. What they discover is bizarre, intriguing, and just plain scary to contemplate. "It was for science, and as long as something is for science, it's worth doing. It's just not necessarily worth repeating." Throughout the book, Mira incorporates snippets from books and interviews to feed the reader some history about the creation of the Intestinal Bodyguard and the scientists behind it. The whole time I kept asking myself, would people really jump at the chance to swallow a parasite pill? Would I? Would the benefits outweigh the fact that a tapeworm* was swimming in your gut? (* beware what you Google after reading this book)The mysteries may have been riddles the characters worked hard to solve, but the reader will find many of them less of a challenge. Be that as it may, it did not take away from the overall enjoyment of the story, in my opinion. The anticipation, as we wait for the characters to come to the same realizations we have, was part of what made the story. What I wasn't expecting, however, was the TO BE CONTINUED ending. I am not a fan, but we did learn just enough to hold us over until [b:Symbiogenesis|13641108|Symbiogenesis (Parasitology, #2)|Mira Grant|/assets/nocover/60x80.png|19255873] comes out, though no word on when that will be. Thank you to NetGalley and Orbit Books/Hachette Book Group for the opportunity to read an advanced copy of the book for an honest and fair review. Further reading on the hygiene hypothesis:Scientific American's "Can It Be Bad to Be Too Clean?: The Hygiene Hypothesis"UCLA Health's "Why are Allergies Increasing?"