‘Look here, though! Suppose the letter was brought simply because it contained instructions for reaching the Flat-Iron and so on, which Alexis didn’t want to forget.’
‘Can’t be that. For one thing, he’d have had it handy, in an outer pocket — not tucked away in a case. And besides—’
‘Not necessarily. He’d keep it handy till he got to the place and then he’d tuck it away safely. After all, he sat at the Flat-Iron alone for an hour or so, didn’t he?’
‘Yes, but I was going to say something else. If he wanted to keep on referring to the letter, he’d take — not the cipher, which would be troublesome to read, but the decoded copy.’
‘Of course but — don’t you see, that solves the whole thing! He did take the copy, and the villain said: “Have you brought the letter?”‘ And Alexis, without thinking, handed him the copy, and the villain took that and destroyed that, forgetting that the original might be on the body too.’
‘You’re right,’ said Wimsey, ‘you’re dead right. That’s exactly what must have happened. Well, that’s that, but it doesn’t get us very much farther. Still, we’ve got some idea of what must have been in the letter, and that will be a great help with the decoding. We’ve also got the idea that the villain may have been a bit of an amateur, and that, is borne out by the letter itself.’
‘How?’
‘Well, there are two lines here at the top, of six letters apiece. Nobody but an amateur would present us with six isolated letters, let alone two sets of six. He’d run the whole show together. There are just about two things these words might be. One: they might be a key to the cipher — a letter-substitution key, but they’re not, because I’ve tried them, and anyway, nobody would be quite fool enough to send keyword and cipher together on the same sheet of paper. They might, of course, be, a key-word or words for the next letter, but I don’t think so. Six letters is very short for the type of code I have in mind, and words of twelve letters with no repeating letter are very rare in any language.’.
‘Wouldn’t any word do, if you left out the repeated letters?’
‘It would but judging by Alexis careful marking of his dictionary, that simple fact does not seem to have occurred to these amateurs. Well, then, if these words are not, keys to a cipher, I suggest that they represent an address, or, more probably, an address and date. They’re in the right place for it. I don’t mean a whole address, of course — just the name of a town — say Berlin or London — and the date below it.’
‘That’s possible.’
‘We can but try. Now we don’t know much about the town, except that the letters are said to have come from Czechoslovakia. But we might get the date.’
‘How would that be written?’
‘Let’s see. The letters may just represent the figures of the day, month and year. That means that one of them is an arbitrary fill-up letter, because you can’t have an odd number of letters, and a double figure for the number of the months is quite impossible, since the letter arrived here on June 17th. I don’t quite know how long the post takes from places in Central Europe, but surely not more than three or four days at the very outside. That means it must have been posted After the 10th of June. If the letters do not stand for numbers, then I suggest that RBEXMG stands either for something-teen June or June something-teen. Now, to represent figures our code-merchant may have taken 1=A, 2=B, 3=C, and so on, or he may have taken 1 as the first letter of the code-word and so on. The first would be more sensible, because it wouldn’t give the code away.” So we’ll suppose that 1 =A, so that he originally wrote A? JUNE or JUNE A? and then coded the letters in, the ordinary, way, the? standing for the unknown figure, which must be less than 5. Very good. Now, is he more likely to have written June something-teen or something-teen June?’
‘Most English people write the day first and the month second. Business people at any rate, though old-fashioned ladies still stick to putting the month first.’
‘All right.’ We’ll try something-teen June first and say that RBEXMG stands for A? June. Very good. Now we’ll see what we can make of that. Let’s write it out in pairs. We’ll leave out RB for the moment and start with EX. Now EX=JU. Now there’s one point about this code that is rather helpful in decoding. Supposing two letters come next door to one another in the code-diagram, either horizontally or vertically, you’ll find that the code pair and the clear pair have a letter in common. You don’t get that? Well, look! Take our old key-word SQUANDER, written in the diagram like this:
S
Q
U
A
N
D
E
R
If you’re coding the pair of letters DE, then, by taking the letters to the right of them (by the horizontal rule) you get DÉER; the letter B appears both in code and clear. And the same for letters that immediately follow one another in a vertical line. Now, in our first pair EX= JU, this doesn’t
The hypothesis that RBEXMG represented a date written entirely in numerals proved to be untenable, and for brevity’s sake, the calculations relating to this supposition are omitted.
happen, some may provisionally write them down in diagonal form
J
E
X
U