„The Master Key: An Electrical Fairy Tale” was one of Baum’s earliest full length fantasy books for children, published in 1901 just one year after „The Wonderful Wizard of Oz”. Rob Joslyn is in most respects an ordinary American teenager; his one distinguishing peculiarity is his passion for the new science and craft of electricity. He has his own laboratory in the attic of the family home, and has rigged the house with his electrical gadgets. One day, amid the bewildering cluster of circuits and wires in his workshop, Rob causes a blinding flash of light – from which emerges the Demon of Electricity. A young boy receives a series of „gifts”, electrical gifts, and has a series of unusual adventures. Rob travels the world, rendering assistance to European heads of state and narrowly escaping disaster at the hands of „primitive” cannibals, Turks and Tatars, pirates, and evil scientists who try to steal his inventions.