Robert Silverberg 
Tom O’Bedlam [EPUB ebook] 

The 22nd century, 150 years after the Dust War destroyed America’s Mid-West, and much else besides. California is a last outpost for survival and reclamation during a long epidemic of all-purpose despair.The extraordinary cult of 'Tumbonde, ’ a former taxi driver its prophet and leader, predicts the imminent arrival on earth of 'Gods’ from the stars. The movement grows daily.Tom O’Bedlam, an apparent madman, prey since childhood to visions which seem to confirm 'Tumbonde, ’ goes even further. He can, he will, help others to make the Crossing. If the world doesn’t go too man too soon. If well-meaning 'rationalists’ don’t lock him away . . .