Sprites are glowing orbs of white light crackling with white energy that haunt the ruin of London after MEDUSA  self-destructs. Sprites are created from energy left over from MEDUSA , and are named so by the Londoners who survived MEDUSA. Sprite are most numeorus in what Londoners call "hot spots".The most common sprite zone is "Electric Lane" where the core of MEDUSA fell after melting its way through the seven tiers of london so its residue is strongest here.In A Darkling Plain Harrowbarrow came through electric lane and it was damaged by the sprites.