Juliet's a worrywart, and no wonder! Her little sister, Oaf, follows her around taking notes and singing 'The Irritating Song' all day long. Her parents are always arguing about Dad's clutter. Nana's so tired of craft lessons that she starts barbecuing things in the middle of the night. And Juliet's friends Lindsay and Gemma are competing to see which of them is her best friend. Juliet can't fit in any more worries!

But then she makes a remarkable discovery. Behind the wallpaper in her new bedroom, Juliet uncovers an old painting of a very special tree. Nana remembers it well: it's the Worry Tree, and with the help of the Worry Tree animals, Juliet just might be able to solve some of life's big problems.