Bart the Bard is unsure of the direction his life is going--he certainly never expected his singing to gain magical properties. But something much more concerning unexpectedly happens when Fiona Featherly, his half-siren teacher, leaves the castle without telling anyone where she is going. Bart, his talking cat Wilbur, and their friends Edgar and Karen must set out to help Fiona before it's too late to bring her back. But will she want to return?