The Columbian Exposition has transformed Chicago into a vision of the bright shining future. However, the electric lights that turn night to day bring no joy to Kitty Hawthorne, and not just because they are the work of her employer's chief rival. Now Edison wants her to abandon her investigation of Tesla's alternating current system and look into a mysterious newcomer. Who is Samuel Gillian, who devises calculating machinery as easily as he builds flying machines?