Adam, who has muscular dystrophy, and five other terminally ill teens give up their failing bodies to inhabit weaponized tools in The Six, the first young-adult novel by Mark Alpert ’82. Living inside steel armor and silicon circuits, these young “pioneers” defend the human race against Sigma, the artificial-intelligence program created by Adam’s genius father that has gone rogue. Alpert, the author of four adult science thrillers, weaves real theories and technologies into the plot.