The second chapter here pretty much kills any pretence that this series is "for young readers" — this is the darkest the Discworld books have ever got, and I found it really very unpleasant. The rapid transition back to bouncy comedy that followed was difficult to swallow.
As with the previous Tiffany Aching books, there are an awful lot of recycled jokes from earlier in the series; this one's also very cameo-heavy. Perhaps it's too easy to read the influence of Pratchett's illness into this...
ISBN 0385611072.