Mungo Morrison is a young mole who is due to begin work at his proud father's side in their hometown's legendary gold mine. While his best friends are excited to be in the mine, Mungo secretly dreams of becoming a professional footballer. However, desperate not to upset his father, as well as being a small mole and unable to play football in bright light, Mungo sadly resigns himself to life as a miner. When the mine is forced to shut down after a mysterious accident, an evil and gold-obsessed...