I owe Emily Rodda many happy hours from my childhood, and now I owe her even more from my adulthood. Even though this is a middle-grade/teen book, there's a timeless, classic quality to Rodda's writing that makes the story engaging even for adults - like the Chronicles of Narnia, or Roald Dahl.
Derry, the main character, is the heart and soul of the text, and he carries the story beautifully. A crippled, intelligent boy with no memory of his past, he nevertheless knows that he can read - an incredibly rare, and forbidden skill. He holds his own counsel, watching the other more dashing characters and balancing their bravery with his wise decisions. Joining Derry is Num, the quirky, empathetic sidekick that every MC needs; Straw, the bold heroine with a will of steel; and Cat, a quicksilver charmer who is brash and cunning. These four go on a classic adventure to find a lost hero, confront tyranny, prevent a war, uncover mysterious creatures, and discover their own hidden (magical) talents.
The narrative is deceptively simple, but it twists curiously when you least expect it. The characters have layers, and the overall ensemble are perfect for the story and each other. There are little mysteries woven into the text that keep the reader guessing even as you form a pretty good idea of what is going on. Not going to lie, I found many echoes of Deltora Quest in this trilogy - side characters cut from the same cloth, themes of deceived innocence expressed in the same ways, and that sense of a great secret at the heart of the story. Not that that's necessarily a bad thing, just noteworthy. The magic is unobtrusive - a side presence in the text that mostly manifests as telepathy and not much else, which is quite refreshing.
Overall, I would have no hesitation recommending this to its target market of young adventure/fantasy readers, and would even recommend it to adults like me who hold a nostalgic place for Rodda in their hearts.