The Second Sleep by Robert Harris

It’s eight hundred years since the collapse of the world as we know. Our civilisation has done a full 360-degree loop and gone back to the basics. No planes, no cars, no IT technology and very few relics of what we have created. After a few hundred years of “dark ages” comes an era similar to medieval times with religion ruling supreme and man living in isolated, cohesive communities.
Christopher Fairfax, a young priest, arrives to such a small village to bury Father Lacey, a parish priest who fell to his death in a secluded area called the Devil’s Chair. Christopher discovers heretical writings of an antiquarian society pertaining to professor Morgensten who anticipated the end of our world hundreds of years earlier. It is a heresy to investigate such writings, but Christopher can’t help himself. With the help of lady Durston and Captain Hancock he embarks on a very dangerous quest – a quest for knowledge.
The Second Sleep is an absorbing fantasy tale about the downfall of man as well as man’s drive to discover the truth and to reinvent himself.