"The Diamond Age" is characterized by two intersecting, almost equally-developed story lines: the social downfall of the nanotech engineer designer of the Primer, John Percival Hackworth, who makes an illegal copy of the Primer for his own young daughter, Fiona, and Nell's education through her independent work with the Primer after her brother Harv steals it from Hackworth. Hackworth's crime becomes known to Lord Finkle-McGraw and Dr. X, the black market engineer whose compiler Hackworth used to create the copy of the Primer, and each man attempts to exploit Hackworth to advance their opposing goals. A third storyline follows actress ("ractor") Miranda Redpath, who voices most of the Primer characters who interact with Nell and essentially becomes Nell's surrogate mother. Later Miranda's storyline is taken over by her boss, Carl Hollywood, after Miranda disappears in her quest to find Nell.