What would happen if earth were invaded by parasitic aliens, also known as "souls", who took over human bodies? What would happen if one of the human souls refused to give up, so that 2 souls were in the host body, one alien and one human? This is the premise behind Stephenie Meyer's book, The Host. The invading soul then has the same memories and emotions as the human soul. It makes for an interesting premise and a fun read.
The book is over 600 pages long but reads like a much shorter book although the plot does lag at times and it takes awhile to really get into the story. I liked her exploration of complicated relationships stemming from 2 souls in one body. It keeps the book from being strictly science fiction because she does spend alot of time on the relationships instead of focussing more on the details of the invading aliens. I also appreciated her exploration of prejudices and prejudgments based on stereotypes, which in this case is the prejudice between the humans and the aliens. Along the way, they discover that their preformed opinions are often false. Of course, there are those who hold to their prejudices and make life difficult for Wanderer (the alien soul) but there are the others who look past their prejudices and find that the individual soul is what really matters.
The book, although written as adult fiction unlike her Twilight series, is clean enough for teens to read. There are just a few minor swear words, some violence, and some romantic relationships, but nothing particularly offensive. Rated PG.