chunk: Rob is 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". He 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 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.
  During the first week, the Demon gives Rob three gifts:
  a silver box of food tablets, each one of which provides sufficient nourishment for a whole day