〃That's OK；〃 Schofield said。 〃We can fix that。〃
Something else that she had said； however； troubled him。 Schofield had been told about the 〃solar flare〃 phenomenon on his way to Wilkes； but he didn't know exactly what it was。 All he knew was that it disrupted the electromagnetic spectrum and； in doing so； prevented any sort of radio munication。
〃Tell me about solar flares；〃 he said to Abby。
〃There isn't really much to tell；〃 Abby replied。 〃We don't really know that much about them。 Solar flare is actually the term used to describe a brief high…temperature explosion on the surface of the sun； what most people would call a sunspot。 When a sunspot occurs； it emits a huge amount of ultraviolet radiation。 A huge amount。 Like ordinary heat from the sun； this radiation travels through space toward the Earth。 When it gets here； it contaminates our ionosphere； turning it into a thick blanket of electromagnetic mayhem。 Satellites bee useless because radio signals from the Earth can't penetrate the contaminated ionosphere。 Similarly； signals ing from satellites down to the Earth can't get through the ionosphere either。 Radio munication bees impossible。〃
Abby suddenly looked about her。 Her eyes fell on one of the puter screens next to her。 〃Actually； we have some weather…monitoring gear in here。 If you'll just give me a minute； I might be able to show you what I mean。〃
〃Sure；〃 Schofield said as Abby switched on the puter next to her。
The puter hummed to life。 Once it was up and running； Abby clicked through various screens until she came to the one she wanted。 It was a satellite map of southeastern Antarctica； overlaid with multicolored patches。 A barometric weather map。 Like the ones on the evening news。
〃This is a snapshot of the eastern Antarctic weather system for〃…Abby looked at the date in the corner of the screen… 〃two days ago。〃 She looked around at Schofield。 〃It was probably one of the last ones we got before the solar flare moved in and cut us off from the weather satellite。〃
She clicked her mouse。 Another screen came up。 〃Oh； wait； here's another one。 There it is；〃 she said。
It filled half the screen。
An enormous yellow…white blob of atmospheric disturbance。 It filled the entire left…hand side of the map； smothering nearly half of the pictured Antarctic coastline。 In real terms； Schofield thought； the solar flare must have been absolutely enormous。
〃And that is your solar flare； Lieutenant；〃 Abby said。 She turned to look at Schofield。 〃It must have moved eastward after this shot was taken and covered us； too。〃
Schofield stared at the yellow…white blob superimposed on the Antarctic coastline。 There were slight discolorations in it； red and orange patches； even some black ones。
Abby said； 〃Since they usually explode in one section of the sun's surface； solar flares usually only affect defined areas。 One station might have a total radio blackout while another； two hundred miles away； will have all of its systems working just fine。〃
Schofield stared at the screen。 〃How long do they last？〃
Abby shrugged。 〃A day。 Sometimes two。 However long it takes for all the radiation to make the trip from the sun to the Earth。 Depends on how large the original sunspot was。〃
〃How long will this one last？〃
Abby turned back to face her puter。 She looked at the depiction of the solar flare on the screen； pursed her lips in thought。
〃I don't know。 It's a big one。 I'd say about five days；〃 she said。
A short silence followed as what she said sank in to everyone in the room。
〃Five days；〃 Rebound breathed from behind Schofield。
Schofield was frowning in thought。 Abby： 〃You say it disrupts the ionosphere； right？〃
〃Right。〃
〃And the ionosphere is 。。。〃
〃The layer of the Earth's atmosphere about 50 to 250 miles up；〃 Abby said。 〃It's called the ionosphere because the air in it is filled with ionized molecules。〃
Schofield said； 〃OK。 So； a solar flare explodes on the surface of the sun and the energy it emits travels down to Earth； where it disrupts the ionosphere； which turns into a shield through which radio signals can't pass； right？〃
〃Right。〃
Schofield looked at the screen again and stared at the black splotches on the yellow…white graphic representation of the solar flare。 There was one larger black hole in the middle of the yellow…white blob that held his attention。
〃Is it uniform？〃 he asked。
〃Uniform？〃 Abby blinked； not prehending。
〃Is the shield uniform in its strength？ Or does it have weak points； inconsistencies； breaks in the shield that could be penetrated by radio signals？ Like these black spots here。〃
Abby said； 〃It would be possible to penetrate them； but it would be difficult。 The break in the flare would have to be directly over this station。〃
〃Uh…huh；〃 Schofield said。 〃Is there any way that you could figure out when or if one of those breaks would be directly over us？ Like； maybe； this one here。〃
Schofield pointed at the large black hole in the center of the yellow…white blob。
Abby studied the screen； evaluated the possibilities。
Finally； she said； 〃There might be a way。 If I can bring up some previous images of the flare； I should be able to plot how fast it's traveling across the continent and in what direction。 If I can do that； then I should be able to make a rough plot of its course。〃
〃Just do what you can；〃 Schofield said； 〃and call me if you find anything。 I want to know when one of those breaks is going to pass over this station； so we can be ready to send a radio signal to McMurdo when it does。〃
〃You'll have to fix the antenna outside…〃
〃I'm already on it；〃 Schofield said。 〃You just find me a break in that flare。 We'll get your antenna up again。〃
In Washington； Alison Cameron was also sitting in front of a puter。
She was in a small puter lab in the Post's offices。 A microcrofilm viewing machine sat in the corner。 Filing cabinets lined two of the four walls。 Half a dozen puters filled the rest of the space in the small lab。
Alison found the screen she was looking for。 The All…States Library Database。
There is a popular urban myth that the FBI has a tap on every library borrowing puter in the country and they use this facility to track down serial killers。 The killer quotes Lowell at a homicide scene； so the FBI checks up on every library in the country to see who's been borrowing Lowell。 Like all good urban myths； this is only a half…truth。 There is a system （it is an updatable CD…ROM service） that cross…links every library puter in the country； telling the user where a certain book can be found。 It doesn't list the names of every person who has borrowed that book。 It just tells you where a particular book is located。 You can search for a book in several ways： by the author； by the book's title； or even by any unusual keywords that appear in the text of a book。 The All…States Library Database was one such service。
Alison stared at the screen in front of her。 She tabbed down to the SEARCH BY KEYWORD button。 She typed：
ANTARCTICA。
The puter whirred for about ten seconds； and the results of the search came up on the screen：
1；856；157 ENTRIES FOUND。 WOULD YOU LIKE TO SEE A LIST？
Great。 One million； eight hundred and fifty thousand books contained the word Antarctica in some way or another。 That was no help。
Alison thought for a second。 She'd need a narrower key word； something a lot more specific。 She got an idea。 It was a long shot； perhaps a little too specific。 But she thought it was worth a try anyway。 She typed：
LATITUDE …66。5° LONGITUDE 115° 20' 12〃
The puter whirred as it searched。 This time the search didn't take long at all。 The results came up on the screen：
6 ENTRIES FOUND。 WOULD YOU LIKE TO SEE A LIST？
〃You bet your ass I'd like to see a list；〃 Alison said。 She hit the 〃Y〃 key for 〃Yes〃 and a new screen appeared。 On it was a list of book titles and their locations。
ALL…STATES LIBRARY DATABASE
SEARCH BY KEYWORD
SEARCH STRING USED：LATITUDE …66。5°
LONGITUDE 115° 20' 12〃
NO。 OF ENTRIES FOUND： 6
TITLE
AUTHOR
LOCATION
YEAR
DOCTORAL THESIS
LLEWELLYN； D。 K。
STAMFORD；