'I-I don't. But I know what this message means.'
'You do?' cried Davenport.
'Of course. It's meaning is transparent. I suspected it halfway through your story. And I was sure of it once I read the reconstruction of the conversations between Strauss and Jennings. You would understand it yourself, gentlemen, if you would only stop to think.'
'See here,' said Ashley in exasperation, 'you said you don't know what the items mean.'
'I don't. I said I know what the message means.'
'What is the message if it is not the items? Is it the paper, for Heaven's sake?'
'Yes, in a way.'
'You mean invisible ink or something like that?'
'No! Why is it so hard for you to understand, when you yourself stand on the brink?'
Davenport leaned toward Ashley and said in a low voice, 'Sir, will you let me handle it, please?'
Ashley snorted, then said in a stifled manner, 'Go ahead.'
'Dr. Urth,' said Davenport, 'will you give us your analysis?'
'Ah! Well, all right.' The little extraterrologist settled back in his chair and mopped his damp forehead on his sleeve. 'Let's consider the message. If you accept the quartered circle and the arrow as directing you to me, that leaves seven items. If these indeed refer to seven craters, six of them, at least, must be designed merely to distract, since the Device surely cannot be in more than one place. It contained no movable or detachable parts-it was all one piece.
'Then, too, none of the items are straightforward. SU might, by your interpretation, mean any place on the other side of the Moon, which is an area the size of South America. Again PC/2 can mean "Tycho," as Mr. Ashley says, or it can mean "halfway between Ptolemaeus and Copernicus," as Mr. Davenport thought, or for that matter "halfway between Plato and Cassini." To be sure, XY2 could mean "Alfonsus"-very ingenious interpretation, that-but it could refer to some coordinate system in which the
Y coordinate was the square of the X coordinate. Similarly C-C would mean "Bond" or it could mean "halfway between Cassini and Copernicus." F/A could mean "Newton" or it could mean "between Fabricius and Archimedes."
'In short, the items have so many meanings that they are meaningless. Even if one of them had meaning, it could not be selected from among the others, so that it is only sensible to suppose that all the items are merely red herrings.
'It is necessary, then, to determine what about the message is completely unambiguous, what is perfectly clear. The answer to that can only be that it is a message, that it is a clue to a hiding place. That is the one thing we are certain about isn't it?'
Davenport nodded, then said cautiously, 'At least, we think we are certain of it.'
'Well, you have referred to this message as the key to the whole matter. You have acted as though it were the crucial clue. Jennings himself referred to the Device as a key or a clue. If we combine this serious view of the matter with Jennings' penchant for puns, a penchant which may have been heightened by the mind-tampering Device he was carrying--So let me tell you a story.
'In the last half of the sixteenth century, there lived a German Jesuit in Rome. He was a mathematician and astronomer of note and helped Pope Gregory XIII reform the calendar in 1582, performing all the enormous calculations required. This astronomer admired Copernicus but he did not accept the heliocentric view of the Solar System. He clung to the older belief that the Earth was the center of the Universe.
'In 1650, nearly forty years after the death of this mathematician, the Moon was mapped by another Jesuit, the Italian astronomer, Giovanni Battista Riccioli. He named the craters after astronomers of the past and since he too rejected Copernicus, he selected the largest and most spectacular craters for those who placed the Earth at the center of the Universe-for Ptolemy, Hipparchus, Alfonso X, Tycho Brahe.
The biggest crater Riccioli could find he reserved for his German Jesuit predecessor.
This crater is actually only the second largest of the craters visible from Earth. The only larger crater is Bailly, which is right on the Moon's limb and is therefore very difficult to see from the Earth. Riccioli ignored it, and it was named for an astronomer who lived a century after his time and who was guillotined during the French Revolution.'
Ashley was listening to all this restlessly. 'But what has this to do with the message?'
'Why, everything,' said Urth, with some surprise. 'Did you not call this message the key to the whole business? Isn't it the crucial clue?'
'Yes, of course.'
'Is there any doubt that we are dealing with something that is a clue or key to something else?'
'No, there isn't,' said Ashley.
'Well, then--The name of the German Jesuit I have been speaking of is Christoph Klau-pronounced "klow." Don't you see the pun? Klau-clue?'
Ashley's entire body seemed to grow flabby with disappointment. 'Farfetched,' he muttered.
Davenport said anxiously, 'Dr. Urth, there is no feature on the Moon named Klau as far as I know.'
'Of course not,' said Urth excitedly. That is the whole point. At this period of history, the last half of the sixteenth century, European scholars were Latinizing their names. Klau did so. In place of the German "u", he made use of the equivalent letter, the Latin "v". He then added an "ius" ending typical of Latin names and Christoph Klau became Christopher Clavius, and I suppose you are all aware of the giant crater we call Clavius.'
'But-' began Davenport.
'Don't "but" me,' said Urth. 'Just let me point out that the Latin word "clavis" means "key." Now do you see the double and bilingual pun? Klau-clue, Clavius-clavis- key. In his whole life, Jennings could never have made a double, bilingual pun, without the Device. Now he could, and I wonder if death might not have been almost triumphant under the circumstances. And he directed you to me because he knew I would remember his penchant for puns and because he knew I loved them too.' The two men of the Bureau were looking at him wide-eyed.
Urth said solemnly, 'I would suggest you search the shaded rim of Clavius, at that point where the Earth is nearest the zenith.'
Ashley rose. 'Where is your videophone?'
'In the next room."
Ashley dashed. Davenport lingered behind. 'Are you sure. Dr. Urth?'
'Quite sure. But even if I am wrong, I suspect it doesn't matter.'
'What doesn't matter?'
'Whether you find it or not. For if the Ultras find the Device, they will probably be unable to use it.'
'Why do you say that?'
"You asked me if Jennings had ever been a student of mine, but you never asked me about Strauss, who was also a geologist. He was a student of mine a year or so after Jennings. I remember him well.'
'Oh?'
'An unpleasant man. Very cold. It is the hallmark of the Ultras, I think. They are all very cold, very rigid, very sure of themselves. They can't empathize, or they wouldn't speak of killing off billions of human beings. What emotions they possess are icy ones, self-absorbed ones, feelings incapable of spanning the distance between two human beings.'
'I think I see.'
'I'm sure you do. The conversation reconstructed from Strauss's ravings showed us he could not manipulate the Device. He lacked the emotional intensity, or the type of necessary emotion. I imagine all Ultras would. Jennings, who was not an Ultra, could manipulate it. Anyone who could use the Device would, I suspect, be incapable of deliberate cold-blooded cruelty. He might strike out of panic fear as Jennings struck at Strauss, but never out of calculation, as Strauss tried to strike at Jennings. In short, to put it tritely, I think the Device can be actuated by love, but never by hate, and the Ultras are nothing if not haters.'
Davenport nodded. 'I hope you're right. But then-why were you so suspicious of the government's motives if you felt the wrong men could not manipulate the Device?'
Urth shrugged. 'I wanted to make sure you could bluff and rationalize on your feet and make yourself convincingly persuasive at a moment's notice. After all, you may have to face my niece.'