it was dark and dusty in the shadow archive but atleast i had found it the shelves marched off into
the gloom and most of them were empty though there was the occasional box of papers marked sa which
had clearly been forgotten in the move they would be interesting to read later but nothing in them
looked important enough to have excited my co conspirator whoever that might be it would have been
easy to get discouraged but i needed to recover the lidar so i carried on searching for the chimney
i eventually found it at the back of the stacks but there was no sign of the lidar or of any
disturbance to suggest it had fallen that far so i guessed it might have got caught on a ledge
higher up fortunately the chimney was fairly wide but not so wide that i couldnt bridge it and all
those hours on the climbing wall paid off as i climbed up looking for the lost machine as i
suspected it had caught on one of the ledges designed to catch rain so i made ready to lower it back
down but as i moved loose bricks to steady myself part of the inner wall collapsed and to my
amazement i found myself staring into a control room it was very jules verne and wouldnt have looked
out of place on the bridge of the nautilus it must have been cutting edge technology once all brass
and polished instruments there was a map on the wall covered in small bulbs that i assumed would
have lit up to signify activity and a bank of fine nineteenth century telegraph machines in polished
walnut unless i was mistaken i had found douglas blacks command centre under a large circular oak
table in the centre of the room there was a filing system with drawers containing maps of every
nation and the table could be turned like a restaurant lazy susan the walls were lined with
brassbound ledgers and folders marked with what looked like mission code names in amongst them was
the most amazing find blacks codebook it contained a number of keys and best of all a list of
ciphers and when and how they should be used it would be worth a fortune on the bibliophile black
market but i didnt feel like selling it harry might be interested if only for historical reasons but
if not then this would find a home in my own private collection i took a seat by the telegraph and
put my feet up opening the codebook at random to read as with the three emperors operation it maybe
necessary to enhance operational security during the operation itself in that case we moved from
purely letter substitution cryptograms to transposition ciphers and at the urging of baron playfair
other more complicated ciphers like the vi genere and playfair ciphers and variants upon them i was
completely immersed in what i was reading and then it hit me