The Weed that Strings the Hangman's Bag tells that Flavia has a passion for chemistry and the objects this time are her two ""evil"" sisters. When she is about to exert, an unexpected death happens in the Bishop Lacey. The died one is Flavia's favorite puppeteer Rupert. All the ones consider the puppeteer was die of an electric shock. However, for Flavia, it is a game of death controlled by someone and a puppet show without string.