Rex Ex Machina

The domination of the minds of tractable Man is not new. Many men have dreamed of it. Certainly some of them have tried. This man succeeded.
One final lesson—a dying man's last letter to his only son that completes the young man's education.
My dear son:—
The doctors have left and I am told that in a few hours I shall die. In my lifetime the world has progressed from the chaotic turmoil of the early Atomic era to the peacefulness and tranquility of our present age, and I die content.
For ten years I have instructed you in all that you will need for the future. One final lesson remains to be taught.
On the wall of my bedchamber hangs a citation from a grateful government for services too secret to be herein set forth. In past years you have asked me repeatedly about this citation, but each time I have taken pains to avoid a direct answer. Now it is proper that you should know.
Forty years ago I was an obscure Army captain stationed at the Armed Forces Language School in Monterey, California. I had at that time just completed a tour of duty in Korea, a minor skirmish of that era, and despite an excellent reputation for resourcefulness, I had drawn Monterey as my next assignment. An aptitude for foreign languages had led to an instructorship in the Russian department with additional duties instructing in the Slavic tongues.
My life was pleasant and uneventful, and it was with mixed emotions that I received orders to report to Washington for a new duty assignment. The chain of events which precipitated those orders were to change the world....
For while you and I were playing on the lawn of our Monterey home, an unknown Hungarian physicist working under Russian supervision had made a startling discovery. Within a matter of days alarming rumors of his work reached Washington. Our embassies in Moscow and Belgrade reported furious activity in the field of psychic research and large-scale experiments in mass hypnosis. Four of us were selected to investigate the rumors. Before we could commence our undertaking, word reached Washington that the rumors were now actualities. A device capable of the mass hypnosis of great segments of the world's population was rapidly reaching perfection.