Age of Miracles
"When the aliens came to earth they did not make contact with its inhabitants. Instead they set up, overnight, vast shining cities like mountainous gems whose borders men could not penetrate, where nations' bombs and weapons could do no damage. In the impact of these incredible invaders, the world's governments fell apart and new ganglike [sic] regimes arose. Reduced to helplessness on what was once their world, men struggle to find a different way of life... free of war, free of national enmities and united only by a burning desire to share in the interstellar Age of Miracles."--Pg. [4] of cover.