Maggin, Swan and Hunt relate the final Valdemar story in Superman 395 (May 1984).
Superman is convinced that Valdemar has something to do with the mind control he knows he is experiencing. He gave the endorsement for president against his will and better judgment. Heading back to their hidden valley, he undergoes a series of challenges to prove himself worthy. The final one has him entering a cave.
There, he experiences a vision of the world a year into the future, with the columnist now a deadly totalitarian leader. Perry and Alice are back together, reluctantly, as he is concealing the fact that he is working with the underground.
Leaving the cave, Superman finds he is still in the present, but now knows what is truly going on. He finds and destroys the Soviet satellite.
While it was good to see Valdemar and his village again, overall I find this story a bust.