Love
The concept of love is an unusual one in this novel, because zombies are not meant to feel emotions such as love. However, R quickly forms an affection that deepens through the book, for Julie, Indeed, the author may be trying to highlight that no matter how different or unworthy people feel, they are all capable of finding love.
Evil
In almost all zombie films and books, zombies themselves are portrayed as a source of evil and destruction to the world. This book too gives this impression, with R witnessing zombies eating humans and fighting amongst each other. However, the author introduces the idea that things may not always be what they seem – that is, R refuses to be categorized as a flesh-eating monster, and instead saves Julie and later the Undead, thereby showing that a savior can come in all forms.
Humanity
This concept is explored profoundly during the course of the book. R may have been made to destroy mankind, but a part of him retains the humanity he thought he lost when he was reanimated as a zombie, so he feels guilt when he kills, for example, Perrie. Indeed, the actual humans in the novel, like General Grigio, are the ones who lack true humanity, with their sadistic desire to massacre all the Undead.
