Jessie is the main character. She is a fourteen-year-old girl who trusts technology more than any of the people in her life.
Jessie's mother has become increasingly ill and dependent on some kind of medicine.
Rosie and Daisy are Jessie's four-year-old twin sisters.
Granny Annie is Jessie's grandmother. She sometimes takes the twins to her house because Jessie isn't able to care for them and her mother too.
Cookie is Granny Annie's black and white cat.
Agent C (Catalyst) takes the role of a worker from the Animal Control Department in Jessie's Journey. (He takes different roles in other ebooks of this series.)
Mr. Forester owns a used bicycle shop and also repairs computers in his back room.
Ran is a sixteen-year-old boy who works for Mr. Forester. His name is short for "Random".
Mr. Wolf is the wealthy man who owns Jessie's house and many other buildings in town. He wields enough power to frighten most people.
Percy is Jessie's friend. The girls have identical electronic journals and communicate long distances with the devices until Jessie's stops working.
Readers can expect Jessie to change over the course of this story. Main characters do that.
Secondary characters mostly support the activities of the main character. They don't usually develop and change very much.
This story follows the usual literary pattern with a conflict between the protagonist (in this case the "champion" is Jessie) and an antagonist ( the "bad guy" she opposes is Mr. Wolf).
Next time I will discuss the plot structure of Jessie's Journey. However, don't expect me to fill in too many details. You will have to read the ebook when it is published to find out how everything turns out.