three, while in one corner is a much larger and thicker 
cross and two smaller crosses not so symmetrical.  This 
group represents the element of chance; and you will at 
least gain a hint of the truth if you reflect that eight is 
the cube of two, and twenty-seven of three.” 
Bevan looked intelligent. 
“On the return march,” continued Duguesclin, “Dodu 
said, ‘The spy is on the watch.  But count the letters in 
the name of Aristotle’s favourite disciple.’  I guessed (as 
he intended me to do) that he did not mean Aris-
totle.  He wished to suggest Plato, and so Socrates; 
hence I counted A-L-C-I-B-I-A-D-E-S = 10, and thus 
completely baffled the spy for that day.  The following 
day he rapped out ‘Rahu’ very emphatically, meaning 
that the next lunar eclipse would be the proper moment 
for our evasion, and spent the rest of the day in small 
talk, so as to lull the suspicions of the spy.  For three 
days he had no opportunity of saying anything, being in 
the hospital with fever.  On the fourth day:  ‘I have dis-
covered that spy is a damned swine of an opium-
smoking lieutenant from Toulon.  We have him; he 
doesn’t know Paris.  Now then—draw a line from the 
Gare de l’Est to the Etoile; erect an equilateral triangle 
on that line.  Think of the name of the world-famous 
man who lives at the apex.’  (This was a touch of super-
genius, as it forced me to use the English alphabet for 
the basis of the cipher, and the spy spoke no language 
but his own, except a little Swiss.)  ‘From this time I 
shall communicate in a cipher of the direct additive nu-
merical order, and the key shall be his name.’ 
“It was only my incomparably strong constitution 
which enabled me to add the task of deciphering his 
conversation to that imposed by Government.  To 
memorise perfectly a cipher communication of half-an-
hour is no mean feat of mnemonics, especially when the 
deciphered message is itself couched in the obscurest 
symbolism.  The spy must have thought his reason in 
danger if he succeeded in reading the hieroglyphs which