Cusp

In 2031, a solar flare of incalculable power shifts the Sun’s position as two immense walls erupt out of the earth, encircling it along the equator and from pole to pole. The climatic and geographical chaos that follows pushes civilization to the brink of destruction, and brings about a new world order.
 
Twenty years later, as a fractured humanity struggles to solve the mystery of the Rings that straddle Earth, an enigmatic entity is pushing its own plan for human evolution, using the supercomputer known as CUSP—the first computer designed to run on the software of the human mind.
 
“Metzger takes cutting-edge science, roils it with startling action, and grabs you on a rocket-propelled ride. Cusp is hard science fiction at its best.”—David Brin

 “Audacious.”—Science Fiction Weekly

“Minds will boggle at the extravagance of Metzger’s imagination.”—Kirkus Reviews