Bwbach is a mischievous, magical house sprite who protects his empty cottage while longing for the day when a new family will move in and make it a home again. When strangers visit the cottage, he thinks that maybe his wishes have come true - but instead, the visitors dismantle the cottage stone by stone and take it away! Its disappearance leaves Bwbach homeless and his magical powers waning.
The wise Fairy King tells Bwbach to the houses of Ffagan near the fortress of Didius to save his cottage. On his journey over land and under water he is helped by animals, birds, school children, and even monster called a Waterleaper.
Will Bwbach succeed in his quest to reach the houses of Ffagan? And what will he find, if he gets there?
(Also available in Welsh as "Y Bwbach Bach Unig")