dors venabili knew that leggen would not willingly go upperside now. he would have to be forced.

first, she checked the library and the dining areas again. then she called seldons room. finally, she went up there and signaled at the door. when seldon did not respond, she had the floor manager open it. he wasnt there. she questioned some of those who, over the last few weeks, had come to know him. no one had seen him.

well, then, she would make leggen take her upperside. by now, though, it was night. he would object strenuously and how long could she spend arguing if hari seldon was trapped up there on a freezing night with sleet turning to snow?

a thought occurred to her and she rushed to the small university computer, which kept track of the doings of the students, faculty, and service staff. her fingers flew over the keys and she soon had what she wanted. there were three of them in another part of the campus. she signed out for a small glidecart to take her over and found the domicile she was looking for. surely, one of them would be available--or findable. fortune was with her. the first door at which she signaled was answered by a query light. she punched in her identification number, which included her department affiliation. the door opened and a plump middle-aged man stared out at her. he had obviously been washing up before dinner. his dark blond hair was askew and he was not wearing any upper garment. he said, "sorry. you catch me at a disadvantage. what can i do for you, dr. venabili?"

she said a bit breathlessly, "youre rogen benastra, the chief seismologist, arent you?"

"yes."

"this is an emergency. i must see the seismological records for upperside for the last few hours."

benastra stared at her. "why? nothings happened. id know if it had. the seismograph would inform us."

"im not talking about a meteoric impact."

"neither am i. we dont need a seismograph for that. im talking about gravel, pinpoint fractures. nothing today."

"not that either. please. take me to the seismograph and read it for me. this is life or death."

"i have a dinner appointment--"

"i said life or death and i mean it."

benastra said, "i dont see--" but he faded out under dorss glare. he wiped his face, left quick word on his message relay, end struggled into a shirt. they half-ran (under dorss pitiless urging) to the small squat seismology building.

dors, who knew nothing about seismology, said, "down? were going down?"

"below the inhabited levels. of course. the seismograph has to be fixed to bedrock and be removed from the constant clamor and vibration of the city levels."

"but how can you tell whats happening upperside from down here?"

"the seismograph is wired to a set of pressure transducers located within the thickness of the dome. the impact of a speck of grit will send the indicator skittering off the screen. we can detect the flattening effect on the dome of a high wind. we can--"

"yes, yes," said dors impatiently. she was not here for a lecture on the virtues and refinements of the instruments. "can you detect human footsteps?"

"human footsteps?" benastra looked confused. "thats not likely upperside."

"of course its likely. there were a group of meteorologists upperside this afternoon."

"oh. well, footsteps would scarcely be noticeable."

"it would be noticeable if you looked hard enough and thats what i want you to do."

benastra might have resented the firm note of command in her voice, but, if so, he said nothing. he touched a contact and the computer screen jumped to life. at the extreme right center, there was a fat spot of light, from which a thin horizontal line stretched to the left limit of the screen. there was a tiny wriggle to it, a random non-repetitive seder of little hiccups and these moved steadily leftward. it was almost hypnotic in its effect on dors.

benastra said, "thats as quiet as it can possibly be. anything you see is the result of changing air pressure above, raindrops maybe, the distant whirr of machinery. theres nothing up there."

"all right, but what about a few hours ago? check on the records at fifteen hundred today, for instance. surely, you have some recordings."

benastra gave the computer its necessary instructions and for a second or two there was wild chaos on the screen. then it settled down and again the horizontal line appeared.

"ill sensitize it to maximum," muttered benastra. there were now pronounced hiccups and as they staggered leftward they changed in pattern markedly.

"whats that?" said dors. "tell me."

"since you say there were people up there, venabili, i would guess they were footsteps--the shifting of weight, the impact of shoes. i dont know that i would have guessed it if i hadnt known about the people up there. its what we call a benign vibration, not associated with anything we know to be dangerous."

"can you tell how many people are present?"

"certainly not by eye. you see, were getting a resultant of all the impacts."

"you say not by eye. can the resultant be analyzed into its components by the computer?"

"i doubt it. these are minimal effects and you have to allow for the inevitable noise. the results would be untrustworthy."

"well then. move the time forward till the footstep indications stop. can you make it fast-forward, so to speak?"

"if i do--the kind of fast-forward youre speaking of--then it will all just blur into a straight line with a slight haze above and below. what i can do is move it forward in fifteen-minute stages and study it quickly before moving on."

"good. do that!"

both watched the screen until benastra said, "theres nothing there now. see?"

there was again a line with nothing but tiny uneven hiccups of noise.

"when did the footsteps stop?"

"two hours ago. a trifle more."

"and when they stopped were there fewer than there were earlier?"

benastra looked mildly outraged. "i couldnt tell. i dont think the finest analysis could make a certain decision."

dors pressed her lips together. then she said, "are you testing a transducer--is that what you called it--near the meteorological outlet?"

"yes, thats where the instruments are and thats where the meteorologists would have been." then, unbelievingly, "do you want me to try others in the vicinity? one at a time?"

"no. stay on this one. but keep on going forward at fifteen-minute intervals. one person may have been left behind and may have made his way back to the instruments."

benastra shook his head and muttered something under his breath.

the screen shifted again and dors said sharply, "whats that?" she was pointing.

"i dont know. noise."

"no. its periodic. could it be a single persons footsteps?"

"sure, but it could be a dozen other things too."

"its coming along at about the time of footsteps, isnt it?" then, after a while, she said, "push it forward a little."

he did and when the screen settled down she said, "arent those unevennesses getting bigger?"

"possibly. we can measure them."

"we dont have to. you can see theyre getting bigger. the footsteps are approaching the transducer. go forward again. see when they stop."

after a while benastra said, "they stopped twenty or twenty-five minutes ago."

then cautiously, "whatever they are."

"theyre footsteps," said dors with mountain-moving conviction. "theres a man up there and while you and i have been fooling around here, hes collapsed and hes going to freeze and die. now dont say, whatever they are! just call meteorology and get me jenarr leggen. life or death, i tell you. say so!"

benastra, lips quivering, had passed the stage where he could possibly resist anything this strange and passionate woman demanded. it took no more than three minutes to get leggens hologram on the message platform.

he had been pulled away from his dinner table. there was a napkin in his hand and a suspicious greasiness under his lower lip. his long face was set in a fearful scowl. " life or death? what is this? who are you?" then his eye caught dors, who had moved closer to benastra so that her image would be seen on jenarrs screen. he said, "you again. this is simple harassment."

dors said, "it is not. i have consulted rogen benastra, who is chief seismologist at the university. after you and your party had left upperside, the seismograph shows clear footsteps of one person still there. its my student hari seldon, who went up there in your care and who is now, quite certainly, lying in a collapsed stupor and may not live long.

"you will, therefore, take me up there right now with whatever equipment may be necessary. if you do not do so immediately, i shall proceed to university security--to the president himself, if necessary. one way or another ill get up there and if anything has happened to hari because you delay one minute, i will see to it that you are hauled in for negligence, incompetence--whatever i can make stick--and will have you lose all status and be thrown out of academic life. and if hes dead, of course, thats manslaughter by negligence. or worse, since ive now warned you hes dying."

jenarr, furious, turned to benastra. "did you detect--"

but dors cut in. "he told me what he detected and ive told you. i do not intend to allow you to bulldoze him into confusion. are you coming? now?"

"has it occurred to you that you may be mistaken?" said jenarr, thin-lipped.

"do you know what i can do to you if this is a mischievous false alarm? loss of status works both ways."

"murder doesnt," said dors. "im ready to chance a trial for malicious mischief. are you ready to chance a trial for murder?"

jenarr reddened, perhaps more at the necessity of giving in than at the threat. "ill come, but ill have no mercy on you, young woman, if your student eventually turns out to have been safe within the dome these past three hours."