To Invade New York....

me," I said. "How did you find outwhere I live? And why?"

  "I asked several of the librarians if they knew you. It seems they did.And since you are listed in the telephone book, the rest was simple." Heheld up the green slip of paper. "Was this ALL you found?"

  Well, I thought, childishly pleased, at least I am not one of theinnumerable nameless faces that pour in and out of the library daily."What else was there supposed to be?" I asked pleasantly.

  The little man sank into my favorite leather chair, almost disappearingfrom view. He waved the slip of paper aimlessly. "There must be more toit than this."

  Despite his rudeness I found myself taking a liking to him. He was sointense and so--frightened. "There _was_ a man," I said.

  He leaped to his feet and clutched my coat. I believe he would havetried to shake me had I not been a foot taller and fully fifty poundsheavier than he. "What man!"

  "In the library. He indicated that book and said something to me."

  He leaped onto the chair in his excitement and grasped my shoulders withhis hands. We stood thus eye to eye. "Please!" he begged. "Try toremember! What did he say?"

  "Perhaps you had better tell me what this is all about, Mr...?"

  "Rumplestein. However, believe me, Professor Clarke, it is much betterif you do _not_ know."

  I shook my head, displaying what my colleagues occasionally call astreak of stubbornness. "You have upset me considerably. I feel I am duesome explanation."

  "No! No! No!" He shook his little head vigorously each time.

  "Then I cannot recollect what this man said to me."

  He groaned in dismay and stepped off the chair to the floor. "Verywell," he said, finally. "You force me to reveal this." I waitedpatiently. His head snapped erect. His body stiffened. "I am engaged ina highly secret mission, the purpose of which is to prevent the collapseof this city."

  I frowned. "You're not serious, of course."

  "I have never been more serious in my life!"

  "_Quem Jupiter vult perdere, dementat prius._"

  "What?"

  "Whom Jupiter wishes to ruin, he first drives mad," I said.

  "You think I'm crazy?"

  I didn't like the gleam in his eye and the tightly pressed lips. Ihastily decided I was better off with him gone. These little people, Iam told, can sometimes get extremely violent.

  "I most certainly do," I said, "but that is none of my affair. I willtell you what that man said and then I would appreciate your popping outof my life as you so unceremoniously popped into it."

  "What did he say?" He leaned forward waiting, it would seem, as if thefate of the world hung in the balance.

  "Eight-thirty tonight. You know the place."

  The little man studied the paper, repeating the words. Then he emitted ashriek of ecstasy. "That's it! Now the message is clear! Thank you,Professor Clarke. You have performed a duty towards society and yourcity." He fled down the hall. I heard the front door slam and returnedto my work with a sigh of relief.

  * * * * *

  About eleven o'clock the same evening, weary in body and mind, I waspreparing for bed when there came what I can only describe as a feeblebut urgent rapping on my door. The strange events of the afternooncompletely forgotten, I opened the door. There, in the dim light of thehall, considerably the worse for wear, stood my little visitor of theafternoon. He was bare-headed, his dark curly locks plastered to hisforehead with perspiration. His bowtie was missing and his checkeredsuit was covered with splotches of mud and some darker substance,especially around the left arm which he gingerly supported with hisright hand.

  "Mr. Rumplestein!"

  He shook his head weakly and staggered into the room. "Not Rumplestein,"he said, so low I could hardly hear him. "Tonight it's O'Grady." Hecollapsed on my leather chair, mumbling, "The door."

  I bolted the door and hurried over to him. "What happened to your arm?"

  "Never mind that now," he said stoically.

  Despite his protests I carefully removed his jacket and cut away thesleeve of his shirt. There was an ugly wound on his arm. "How did thishappen?" I asked, horrified.

  "It's nothing," he said. Then he grinned momentarily. "The chap whocaused it is feeling _no_ pain at all!" He closed his eyes and his headbegan to sway. "If you have any liquor," he mumbled, "I feel faint,suddenly--"

  I rummaged through my desk and found a tiny bottle of some cordial acolleague had once brought me as a jest, knowing I do not drink. WhileMr. Rumplestein, or O'Grady, gulped down the liquid I inspected thewound. "A doctor should look at that," I said.

  He shook his head and leaned back in the chair, the top of his head agood twelve inches below the top of the chair.

  "I feel better now," he sighed.

  "Then perhaps you will be good enough to tell me what this is allabout." As I spoke I washed and dressed his wound as best I could. "Yourealize, my good fellow, for all I know you may be wanted by the police,in which case I could be arrested for harboring a criminal."

  "I assure you, Professor Clarke, I am no criminal." He plucked a bit ofmud from his beard and carefully deposited it on the table.

  "But you've been wounded! And you infer you did some bodily harm tosomeone else."

  He chuckled softly. "Bodily harm? I killed him!"

  I recoiled in fright. "I must notify the police!"

  "No! That would ruin everything! New York would be destroyed!!"

  I clucked impatiently. "Please, Mr. Rumplestein, or O'Grady, or whateveryour name is. If you cannot give me an honest answer, I shall be forcedto call the authorities. This nonsense about--"

  He held up his hand and emitted a huge sigh. "Very well," he said, "Iwill tell you what this is all about because my usefulness may come toan end abruptly and you may have to carry on. Listen carefully." Iwaited with mounting impatience.

  "New York," he said after a brief pause, "is a huge, sprawlingmetropolis that breeds within itself the seeds of its own destruction.Transportation." I raised an eyebrow. "At best," he went on, "thetraffic in Manhattan does not flow--it limps. Let one traffic light failand vehicles are backed up for several blocks. True?"

  I nodded. "Yes."

  "Very well. Imagine, then, a situation where, at one given instant everysingle traffic light on this congested island turns green and STAYSgreen." I shuddered at the thought. "Picture the beauty of it," he said."Not red, which would cause all automobiles to stop, but green, thesignal to go! Imagine their mad desire to rush forward in righteousobedience to the law, and their awful frustration to find every otherautomobile and truck obeying the same law, regardless of the directionfrom which it is coming. It has been estimated by noted mathematicianswho are involved in this plan, that within forty-five seconds alltraffic in Manhattan would come to a standstill, it becoming impossiblefor a car to move forward or backward. Oh, what utter chaos!"

  "_Ab homine homini periculum quotidianum_," I said.

  "Eh?"

  "Man is daily in danger from man. An ancient Roman said that."

  "He knew what he was talking about. But this is only Phase One of theplan. A corollary is based upon the axiom that one disabled automobileis equal to ten thousand operating ones."

  "I don't follow."

  * * * * *

  "The highways leading into and out of this island. Regardless of thenumber of lanes, if one automobile breaks down, traffic is immobilizedfor miles. Multiply that by several dozen, all at the same time, on allthe entrances and exits to the island, and no earthly power coulduntangle that situation in less than a week, if then!"

  His words evoked an image of metal monsters, stretched as far as the eyecould see, steam pouring from their overheated radiators as theyraucously bleated for help.

  "All this can be accomplished quite simply and inexpensively," continuedmy bearded little man. "However, what of subsurface transportation?"

  "You mean the subway system?"

  "Exactly. Once again, simplicity is t
he key. What do subway riders useto gain entrance through the turnstiles? Tokens. Let us suppose that onthis same given day the majority of tokens distributed are allfractionally larger than normal. Not enough to be noticed, mind you, butjust enough so they cannot pass through the slots and activate themechanism."

  "But--"

  "Do you realize the absolute ingenuity of this plan? Subway riders bythe thousands will be trying to put tokens _that they paid for_ intoslots that will not receive them! The tremendous howl of