...As Certain As Death and Acids...
The Flavia de Luce series by Alan Bradley is the most endearing crime series I've ever encountered. Imagine Miss Marple crossed with Wednesday Addams, and you can start to get a picture of our dangerously clever young investigator. Flavia is 11 years old, living in a decrepit mansion in the English countryside with her father and two sisters (the source of constant torment and revenge), and constantly running into trouble on her trusty bicycle, Gladys. Whenever she's not wreaking havoc on her bike, she's likely to be found in their comprehensive chemical laboratory learning new mixtures and compounds, and employing them for both good and evil.
This series is the perfect combination of macabre and adorable, a combination I wouldn't have thought possible before reading The Sweetness At The Bottom Of The Pie. Now the series is up to book 7, and I can't get enough! Flavia is dangerously smart, and mischievous to boot, all with the blind innocence of an 11 year old girl. This series can't be recommended highly enough: it is at times chilling or hilarious, gripping or endearing, and is endlessly entertaining.
(Also: keep an eye out for the Flavia de Luce TV series in the pipeline. I'm yet to find a release date, but it's being directed by Sam Mendes (American Beauty, and Skyfall) and is said to be similar in design to BBC's Sherlock. Exciting!)