Fifteen-year-old Jonny Napper spends his summers in London with his enigmatic grandmother, Margaret, where he helps out at his family’s curious sleep accessories store which has been in business for centuries. On the eve of his sixteenth birthday, Margaret tells him of the Dreamworld, a parallel dimension where sleepers leave Reality and embark on a world based on their memories, experiences, and emotions. Margaret has a gift to create individual dreams for customers and reveals to Jonny that he has the genetic ability to do the same. When his mother goes missing, Jonny seeks help in the peculiar world only to discover a long-buried secret that changes everything he thought he knew about his family.