The ending is bittersweet.  The start off book 3 is a little odd compared to the rest of the story, but it is needed as it is the origin story of Gus.  And others.  The group is still traveling, this time they are heading to Alaska.  They don’t know what they will find, but according to Gus’s dad’s journal, the answers are up north.  But there are some side bits when a green compound is found.  The gang wants to stay, and one of the kids really needs to hibernate.  But this is a post-apocalyptic world that is dangerous, so nothing is simple or easy.  Be prepared for death and destruction. Yes that has been evident in all books in this series, but it just gets worse.  But it has to get worse to get better.  I loved this book and how it ended.  I loved it so much I can not bring myself to watch the netflix show for fear it will ruin it.   However, I have recently learned that a new book is imminent.  Can’t wait.