Post-apocalypse
The novel portrays an apocalyptic world where the society is split into those who are fortunate to stay protected inside the world and the outside world filled with beasts, monsters with human shells and unfortunate people who weren't let inside the wall and have to fight for their survival on their own. Jack's family belongs to the less fortunate, and they built their own protective wall out of their home. It is a world where human life is little valued, a world where women have to hide and cruelty a normal part of life.
Love
A young adult novel can hardly go by without the theme of love, even in the grimmest circumstances. The love story between Jack and Kevin becomes the forefront of the plot once the two characters meet. Jack is the strong female character, who trained to survive in the outside world ever since the hell on earth broke loose, but she begins to let her guard down once she gets to know the handsome Kevin. That's why it is even more heartbreaking when Kevin seemingly betrays her when she finally let herself trust him. But, it turns out that he did everything to protect her at the end and their love story turns into a story of hope, selfless dedication and self-sacrifice for the other human being in a world where empathy and morality is scarce.
