Oh yes, this is good.

A "kid's" book, but a kid's book in the vein of Phillip Pullman, or Garth Nix even (who is quoted on the back of my edition as saying he's quite the fan of Hardinge). Heroine Mosca Mye drinks beer and smokes a pipe, not in some juvenile, Francesca Lia Block teenage rebellion way, but because this book is set very loosely in Ye Aulde 18th-Century England, and a 12-year-old girl probably would have drunk beer at that time. I love books that don't spare kids the realities of life.

The twisty plot doesn't quite manage J.K. Rowling-esque surprises (remember the first time you realized it was Quirrell all along?) but isn't completely predictable, either. Besides, you'll love Hardinge's wry turns of phrase and invented curses no matter what the plot is. ("I want my chirfuggin' goose back!")

Read it. Just read it.