Starting at a new school in a small coastal town in England, nine year old Morgwyth hopes to make friends quickly - but as usual, her odd name and extraordinary gifts label her as strangely different. Soon she is confronting bullying, class difference and the staggering forces of two mythical creatures who are threatened by the power of her abilities.
Because Morgwyth can see and hear what birds and animals think, and in her dreams forms a bond with a wolf-weasel creature, she lives between two worlds. Strong, feisty and vulnerable Morgwyth faces cruelty from the class bully Marc Colbrooke and his friends. Luckily her teacher Miss James believes Morgwyth has something special and is pleased to see a friendship develop between Morgwyth and Teresa Finnegan. But Teresa's upper-class mother is dead set against the friendship, preferring to keep her daughter bonded to her own best friend's daughter, Lisa.
Meantime two mythical characters, Sheolduff and Gorth, fearing their survival if Morgwyth discovers her power, use their shapeshifting tricks and illusions to confuse and distract her. When Miss James's engagement ring and other items go missing, Marc and Lisa lead the chorus of accusation against Morgwyth. Will she be able to defeat all these forces and gain recognition for her unique abilities?
When the Magpie Calls is a story of Morgwyth's journey in discovering the power of difference.