Lisa is the protagonist of the novel. She is 10 years old when the plague strikes but almost 12 by the end of the work, making her one of the oldest of the children. From the start, she is very self-sufficient; she is much better at finding supplies than the other children, and she understands the difference between the kinds of supplies children typically want and what they need in order to survive.

In this respect, she is practical, but in other ways, she is rather idealistic. For example, Craig is happy to settle on a farm and grow enough food for him and his sister to survive, and other children believe they can only survive by compromising with the gangs. Lisa, on the other hand, believes that they can survive and thrive without compromising their principles; not only that, but she believes they can eventually return society to normal if they work hard enough.

This emphasis on hard work is key to Lisa’s worldview. She feels that it is important to earn what one has; because of this, she rejects any compromise or deal with the gangs who steal in order to survive, and she mostly refuses to help others who don’t give her something in return.