If there was a cycle of reading Asimov, this would be it! Psychohistory that predicts the behavior of the masses is not very far from the "marketing science" that is applied nowadays. The quest of the "other end of the universe" is worthy of a detective novel! Each book brings a lot of surprises, questioning the solution that was believed found at the end of the previous volume. Mixing the story (that of certain characters) to large (the planets), even if they are virtual, is one of the keys to this success. Exciting from start to finish!