Foucault's Pendulum — Umberto Eco

Three clever editors (who have spent altogether too much time reviewing crackpot manuscripts on the occult by fanatics and dilettantes) decide to have a little fun. They are inspired by an extraordinary fable they heard years before from a suspiciously natty colonel, who claimed to know of a mystic source of power greater than atomic energy.

On a lark, the editors begin randomly feeding esoteric bits of knowledge into an incredible computer capable of inventing connections between all their entries. What they believe they are creating is a long, lazy game--until the game starts taking over....

Here is an incredible journey of thought and history, memory and fantasy, a tour de force as enthralling as anything Umberto Eco--or indeed anyone--has ever devised.