Jessie is the protagonist of the novel. She is the second oldest of five siblings, after Hannah and before Andrew, Nathan, Bartholomew, and Katie. Jessie resents that Hannah is complacent and interested in boys, while Jessie loves adventure and questions the many mysteries of Clifton. She is inquisitive and attentive, the key reasons why Ma chooses Jessie to sneak out of Clifton and seek medicine for the children.

Jessie considers herself to be especially brave. She often brags about taking on dares from the other children and secretly uttering “modern” words the adults have forbidden. As a young girl, she spotted a camera, which she believed was a strange box in a tree, and was beaten for speaking about it. This incident, along with the curious behavior of some of the Clifton adults, leads Jessie to suspect that they are keeping more secrets. When Ma reveals the truth about the village, Jessie is scared and confused. She agrees to the dangerous escape because she wants to save the children from diphtheria. They become her priority and motivation for moving forward.

As Jessie encounters the strange modern world and its frightening outsiders, she confronts her own ignorance, fear, and mistrust of others.