In this story, relationships are built between humans and an invader race of aliens. You'd expect to just hate the invaders, but Stephanie Meyer manages to make them likeable, even sympathetic. There are interesting twists and turns between the relationships that develop between humans, between aliens and even between the human/aliens, or hosts and souls.
Stephanie Meyer's writing has matured a great deal from the Twilight books and really stands up to scrutiny in The Host.
I would definitely recommend this book!