A Red Herring Without Mustard by Alan Bradley

In this book the wonderful Flavia de Luce returns, but this time, while she does use her acute analytic skills and run some chemical experiments, poisons don't play a leading role. Instead, Flavia unravels a mystery that has a number of red herrings--and a fishy smell all around. I think this mystery did a great job bringing the disparate pieces of the story together in a convincing way, even if it took me longer than usual to figure out where things were headed. I'm really enjoying this series.