I was chatting, I recall, with some students about the transuranic elements after my lecture on "The Chain Reaction of Uranium" when a lab instructor tapped me on the shoulder. "There's an army colonel waiting upstairs in your office, Doctor Bailey." I was frowning when I left. A reserve officer who served in Military Intelligence on the Manhattan Project, I sensed something ominous in the visit. The Korean situation already had me in an uneasy mood. My spirits picked up, however, when I entered the office and recognized the tall dignified figure, with grizzled hair, standing by the window. "Jim Armstrong, you old blood-hound." "Hello, Arnold," and my hand was lost in his big fist. Armstrong is a powerfully built man. He played a bone-crushing left end in his college days. You used to need a convoy of light tanks to make a sweep around him. I know; I played against him when I was a blocking back on the Princeton varsity. A former F.B.I. agent, he had one of the toughest and finest minds in Intelligence. Once he picked up a trail, he followed it doggedly. Like the time during the war when he went after government-contract profiteers. Despite faked invoices, bribed witnesses, and strong pressure from higher-ups, he tracked his men down and landed them in jail. "Now, Jim, what's on your mind?" I said after we were both comfortably seated. He put his hand in his tunic and brought out a letter which he handed me. "I want you to read that, Arnold. Yesterday every member of the United Nations received a similar note. No one takes it seriously, regarding it as the work of a peace crank. I'd like to hear what you think about it." I put on my glasses and opened the letter. _Dear Sirs:_ _You are herewith given notice to bring peace and freedom to all peoples within thirty days from this date. We are sick of your broken pledges, your compromises with principle, your verbal shilly-shallying. Give us peace within a month or I shall destroy the earth utterly._ _Chetzisky._ * * * * * I recognized the name immediately. "Chetzisky." A brilliant Polish physicist, a refugee who fled the twin tyrannies of Germany and Russia. Unknown to all but a few, he had played an important role in the Manhattan Project. His opinions and work had won the respect of the Comptons, the Oppenheimers, the Seaborgs; even, it's said, of Einstein himself. His small face, with oddly shining eyes set close together, came vividly to mind. The last time I saw him was in March, 1946, en route to St. Louis for the convention of the American Association for the Advancement of Science. I met him on the train out of Chicago. His conversation was bitter with denunciations of the world's fumblings toward peace.