The Long Mynd by Edward P. Hughes
Baen Books, 1985
Price I paid: 25¢
Not long ago, back in the 1980s, the world had not yet heard of charming. But then came a strange and godlike mutation that affected one child in a million. That child would grow to be a Charmer—one who could, by an act of will, change the form of any substance: coal into diamonds, play money into real money, iron ore into armor plate, water and uranium ore into hydrogen bombs—and the charmed item would appear wherever the Charmer wanted. The White House, the Kremlin, anywhere. It was the end of the world, of course…