Thus, pondering on the mysteries of space and time, of infinity, eternity, and the riddle of the universe--or, to be exact, upon an equation which he was figuring out on the seventeenth leaf of his note-book--Professor Benjamin Hooker wandered into Dupont Circle and absent-mindedly seated himself on the southeast end of a green park bench upon the northwest corner of which reclined a young lady dressed in a tan tailor-made suit. Professor Hooker did not know that he was in Dupont Circle; he did not even know that he was on a green park bench, and, if he had, he would not have known upon which end of it he was. Needless to say, he was entirely ignorant of the presence of the young lady in the tan tailor-made suit. The equation was a very annoying one, and, for some reason or other, he found it impossible to integrate it. With his note-book on his knee, Professor Hooker chewed viciously the rubber tip of his lead-pencil and cursed the devil that was in the figures. And, as he was thus engaged, a clear, well-modulated young voice, which appeared to emanate from a point directly over his right shoulder, remarked, "Why don't you write _x_ in its exponential form, Professor Hooker?" So far as its arousing Professor Hooker to a consciousness of his physical existence was concerned, the voice might have been the murmur of the night breeze. To him, it was less than the voice of conscience. "That's so," mused Professor Hooker. "Of course. Why didn't I think of that before?" And this, as he thought, he proceeded to do. But still the solution would not come. "But you didn't think of it at all, and you haven't even done what I suggested!" declared the voice. Then, for the first time, he looked up over his shoulder. The girl in the tailor-made suit had moved along the bench and was now sitting next him in the closest proximity possible without actual contact. As she sat there, she was slightly taller than Professor Hooker, who, unfortunately, was too preoccupied to be conscious of the trim slenderness of her athletic figure, her alluring cheeks and chin, the long black lashes of her large gray eyes, her low, wide forehead, of the whimsical smile that played about her softly curving lips. He saw none of these things, but he, somehow, received an impression of vigor, poise, certainty, and comprehension. In other words, his reaction was entirely intellectual and not in the slightest degree physical, which made it very much easier for Professor Hooker to sit as he did on that green park bench and say: "Plague take the thing! Got any idea what's the matter with it?" "Let me have your note-book," ordered the young lady, and, without waiting for a reply, removed it genially from his reluctant fingers and annexed the pencil. "There!" she said. "Now, it's simple enough--don't you see? X has the significance of the real part of the complex." "Well," declared Bennie, with obvious admiration, "you're certainly a shark at mathematics!"