I am sure he went up there to jump immediately. But he had been there an hour, now. Perhaps, I thought, he was trying to figure, in a last desperate moment, where his experiment had failed. Trying to find in the mysterious, senseless chaos of embryonic human thought, a reason why he should not die.... The police got me through the crowd, inside the building and into an elevator. I ran down the hall of the thirtieth floor to the room where policemen were working with ropes and steel hooks. I heard one of them say, "We can't reach him. It's no use." I stuck my head out the window, called Marsten's name. But the wind tore the words away, sent them in the opposite direction. He didn't turn his head. I could barely make out his features, dead white and void of expression. "Don't jump, for God's sake!" I called over and over. "Professor, _you were right! The experiment was a success! Listen to me! It was a success!_" I could see the uplifted faces down below, a blanket, a net they had stretched down there, both looking no bigger than a checker square. Marsten didn't seem to hear me, but I kept yelling, trying to make him hear. I fought the wind, and whatever barrier there was between Marsten and myself. But he didn't turn, didn't seem to hear me, seemed unaware of me, of anything that went on around him. I shouted the explanation to him of what I'd suddenly realized: In these ESP tests the receiving impressions are the symbols on the various cards in a deck. Basically, the tests in ESP experiments all come down to one thing--the participants try, without seeing the cards, to identify the symbols on each card in a deck as they draw them from the pack. In reviewing the results of these tests, it often happens that participants, extra-ordinarily gifted with what is called 'psychic ability,' have long runs of picking exact cards. But these runs are sometimes on the cards--_before the one that is being turned, or on the one after the one turned_. In other words, if cards A-B-C-D-E-F-G have been turned, many times the participant will call B when C is turned, C when D is turned, E when F is turned, and so forth. There are various theories for the cause of this factor. It is a factor that comes up time and again. Marsten knew that. But in that intense moment he must have overlooked it. It hadn't occurred to any of the others there, either. We were all too close to the forest to see the trees.... And I screamed at the Professor against the wind and the morning: S-D-K-D-O-A-S-G-X form an acrostic, and they are all one letter in the alphabet _before_ the letters that spell out T-E-L-E-P-A-T-H-Y! Except in the letter A, for Adler. There could not be a letter before A in the alphabet. So, there was no displacement factor on Adler's card. "Marsten, listen to me! Can you hear? Can't you understand? The _displacement factor, Marsten_! The _Displacement Factor_--"