Twelve-year old Gemma loves to draw. Her latest passion is illustrating the story of Jack and the Beanstalk, rendering in heart-stopping detail the terrifying giant, Blunderbore. Then, on a trip to stay with her Aunt Lucy, Gemma's drawing is ripped in a lightning strike. When she hears strange calls for help coming from the beach, Gemma sets off to investigate and discovers that somehow her art has become reality. Jack and Blunderbore are in her world. And Blunderbore has kidnapped Jack.
It's up to Gemma to help him. Can she survive the terrors of Blunderbore's castle, rescue those imprisoned there and work out how to restore the natural order between the two worlds?