The Master Key
The protagonist is a boy named Rob Joslyn. His age is not specified. Baum dedicated the book "To My Son, Robert Stanton Baum," who was born in 1886 and would thus have been about fifteen at the time it was published. Rob, we are told, is
in truth, a typical American boy, possessing an average intelligence not yet regulated by the balance-wheel of experience. The mysteries of electricity were so attractive to his eager nature that he had devoted considerable time and some study to electrical experiment; but his study was the superficial kind that seeks to master only such details as may be required at the moment. Moreover, he was full of boyish recklessness and irresponsibility and therefore difficult to impress with the dignity of science and the gravity of human existence. Life, to him, was a great theater wherein he saw himself the most interesting if not the most important actor, and so enjoyed the play with unbounded enthusiasm.
We are introduced to Rob as an electrical experimenter whose father encourages him and sees that he "never lacked batteries, motors or supplies of any sort." A "net-work[sic] of wires soon ran throughout the house," and the house is full of "bells, bells, bells everywhere, ringing at the right time, the wrong time and all the time. And there were telephones in the different rooms, too, through which Rob could call up the different members of the family just when they did not wish to be disturbed."
Rob loses track of the elaborately interconnected wires, and trying to get a cardboard house to light up, he "experimented in a rather haphazard fashion, connecting this and that wire blindly and by guesswork, in the hope that he would strike the right combination." There is a bright flash, and a being who calls himself the Demon of Electricity appears. He tells Rob that he has accidentally "touched the Master Key of Electricity" and is entitled to "to demand from me three gifts each week for three successive weeks." Rob protests that he does not know what to ask for, and the Demon agrees to select the gifts himself.