SLEEPWALKERS WORLD BY GORDON R. DICKSON 1985
Paradise?
The Energy Crisis: Solved!
The Popualtion Bomb: Defused!
World-Wide Disarmament: A Reality!
But the price may be too high to pay - for the white-hot metal shafts that have plumbed Earth's core to bring back its plenty have awakened a terror that Mankind thought would sleep forever....