"A Hat Full of Sky" by Terry Pratchett is a fantasy novel about a girl who is learning her place as a witch. Early in the novel, Tiffany Aching leaves her home in the chalk country (based on England's chalk country) to act as an apprentice and maid for the elderly witch Miss Level. Her former teacher, Miss Tick, who is also a witch, escorts her to the town of Twoshirts. While waiting for Miss Level to arrive, they are attacked by a hiver. The hiver cannot be killed or seen and it takes over your mind. The encounter is only for a few seconds, and then the hiver leaves but it gives Tiffany and Miss Tick a fright. Miss Level comes along on a broomstick and takes Tiffany to her cottage in the mountains.