The story unfolds when little eight year old Jenny Connolly, after a battle with her conscience, skips school one day in order to avoid a spelling test that she has been dreading. Jenny escapes through the fields to an enchanted wood called Willow Grove. Jenny is no stranger to Willow Grove or to its delightful characters such as Elsa, the wise and gracious deer, Louis Noodle, the self-important owl, Lucy and Oscar Pebble, the excitable young robins, to name but a few. Here in this magical place, Jenny can talk to the animals and delight in their world.

When Jenny arrives in Willow Grove she is shocked by what she sees. It is a scene of devastation; the river is almost dried up causing great anguish for her droll friend Hector, the tortoise. The once majestic Ash tree is shrivelled and fading. The ground is burnt and there is little sign of life. Jenny discovers that her friends have all been living in terror of "the new witch" who has descended upon their once peaceful haven.

The "new witch" is difficult ten year old Marigold Dimple, who has been sent to stay with her aunt Griselda for the summer. Marigold deceives her aunt into thinking she has passed her exams at the academy of magic. Marigold, however, believing school to be a comple waste of her precious time, has not successfully mastered the casting of spells. This does not deter Marigold as she angrily stomps through the woods casting spells here and there causing mayhem at every turn as each of her spells results in a different catastrophe.

Amidst all of this chaos, Jenny and Marigold's paths collide. Each young girl is forced to question her actions and face up to her fears. While both come from very different worlds, their problems are not so different. They realise and learn from mistakes made, they come to understand that things are never quite as bad as they first seem and running away from your problems just makes things worse. The adventure draws to its conclusion with a surprising twist that readers will not expect but thoroughly enjoy.