On his ninth birthday, Gwyn Griffiths is bestowed with five special gifts infused with ancient Welsh magic. But can magic help him find his sister Bethan?

Gwyn investigates the identity of the pale girl in Arianwen's web. Meanwhile, his magical powers are putting a strain on his relationships with Alun and his parents.

When the secret of Gwyn's magic spills out, the school bullies are onto him. However, he finds an unlikely saviour in Pendewi's new pupil, the mysterious Eirlys.

Gwyn searches desperately for his missing Snow Spider. However, when he releases the dreaded toy horse, a deadly storm falls on Pendewi, unleashing the monster of Mabinogion legend.

With his Snow Spider safely returned, Gwyn ventures to battle Efnisien. However, unknown to him, Eirlys and Alun have followed him.