Weed That Strings the Hangman's Bag, The (Flavia de Luce #2) by Alan Bradley; 2011. Softcover.

Flavia de Luce, a dangerously smart eleven-year-old with a passion for chemistry and a genius for solving murders, thinks that her days of crime-solving in the bucolic English hamlet of Bishop’s Lacey are over—until beloved puppeteer Rupert Porson has his own strings sizzled in an unfortunate rendezvous with electricity. But who’d do such a thing, and why? Does the madwoman who lives in Gibbet Wood know more than she’s letting on? What about Porson’s charming but erratic assistant? All clues point toward a suspicious death years earlier and a case the local constables can’t solve—without Flavia’s help. But in getting so close to who’s secretly pulling the strings of this dance of death, has our precocious heroine finally gotten in way over her head?