In dark ages Britain, a time of magic and legend, a powerful druid is bent on destroying the Celtic people. Arthur, a banished warrior, and Merlin, a hermit wizard, embark on a heroic quest to stop the druid and save their people, before the Celts are lost forever and become a myth themselves.

In a world overrun with monsters, Pip and Po's clean up service are the only thing that stands between good and evil.