the trilogy is set in the large city of london. borribles are runaway children, who eventually become "borribled," when they wake up and find their ears have become pointed. visually very similar to the mischievous elves and pixies of english folklore, borribles wear woolen hats pulled low over their ears to avoid being easily identified by the police "woollies". the woollies believe that the borribles' freedom is a threat to the social order and will clip the ears of any borrible in their custody. if their ears are not clipped, borribles will maintain the appearance of a child forever and cease to physically age. being caught by the police is a prospect worse than death for borribles as it will signify the end of their lifestyle and they will become a boring, adventureless adult.