In 1921, Paul Amadeus Dienach, a Swiss-Austrian teacher with fragile health, falls into a one-year-long coma. During this time, his consciousness slides into the future and enters the body of another man in 3906 A.D. When Dienach awakens from his coma, he finds himself back in 1922. Knowing that he doesn't have much time left, he writes a diary, recording whatever he could remember from his amazing experience: the mankind's history...