Jack had a tough childhood. He was bullied because of the way he looked and became introverted. He relied heavily on the close relationship that he shared with his Grandma--a relationship in which they shared one major secret. They had a special type of peripheral vision, which allowed them to see the thin spots in the fabric between our reality and others.
Peripheral is about discovering another world, but it is also about Jack's journey of self-discovery and the relationships he forms along the way that give him the confidence to fight against his biggest bully yet. Bad Jack.