Ever since he discovered the mirror in his absent father's study, Jacob Reckless has been going back and forth from one world to the next - the human world... and the one inside the mirror. He calls it, coincidentally, Mirrorworld. Ever disappointed with his life on the human side, Jacob spends more and more time there, once leaving for three years.
This terrifies his young brother, Will. Will is thoughtful and mild and trusting - the exact opposite of his brother. Will doesn't know where Jacob goes for twelve years, but he worries the whole time.
Then, one day, somehow, Will discovers Jacob's secret. And on that day, Will begins a slow, painful transformation into a monster - a stone-skinned Goyl. Now Jacob, his faithful Mirrorworld Fox (a shapeshifting vixen), and Will's human girlfriend Clara have to traverse Mirrorworld to find Will's cure.
But Mirrorworld is based on fairytales, not Disney movies, and the characters they encounter - seductive Fairies, double-crossing Dwarfs, scissor-handed killers, and the Goyl themselves - aren't as safe as they appear.
This is Cornelia Funke. She wrote Inkheart and The Thief Lord. I desperately wanted to like this. Sometimes I almost did. But most of the time, it was... disappointing.
It was almost like reading a well-developed outline. There was action, there was plot progression, there were truly interesting settings and twists there... but no characterization, no emotion. Jacob, Will, Fox, and Clara - as well as other minor characters, like Hentzau the Goyl soldier and the treasure-hunter Dwarf Valiant - were cardboard cutouts. The reader is told what they're like. Will is nice. Jacob is unhappy. Clara is brave. Fox is protective. There were flashes of what they could have been, but most of the time, they fell flat.
Incidentally, the most interesting character was the Dark Fairy - the villainess, most of the time. I hated her at first. Then one scene came along that really made me want to learn more about her - figure out what made her tick. Unfortunately, Funke abandoned that particular part of her story, and she faded into the realm of cardboard again.
I mentioned that the plot had a lot going for it. It could have been amazing. The angst between the two very different brothers had so much potential. But combine the bad characterization with the rather unenthusiastic writing style and a confusing climax, as well as a last page that begs for a sequel, and you have... the least of Funke's books. Stick with The Thief Lord.