our london akela groups have been scouting for clues in areas with a large german population using the cover of good turn day to visit a number of house sandflats known to be occupied by foreign residents in most cases there was nothing to report which is not a real surprise as v ks group had already vetted alot of them and found nothing to report the breakthrough came when one of the land ladies mentioned that she was sad to see her previous resident leave so suddenly but glad that they had be enable to recommend such a nice replacement for the flat i might have missed the importance of this but we heard the same story at three different addresses in the east end of london all with the same departure date and that coincided with the original arrival of the spy c list touring group from norfolk one of the land ladies had somewhat fortuitously kept a record of the comings and goings of her residents and was able to describe visitors to the departed tenant there had been an increase in the number over the three weeks leading up to their departure and that date coincided with the arrival of the spy c list touring group in the uk i circulated descriptions of the departed tenants to our agents at the port authorities and they were able to confirm that a group matching the description had left the country the day after the spy c list group arrived at kings cross our agents and akela groups in essex and kent were asked to report on the spy c list groups in their neighbourhoods and both teams sent me a list of the touring parties reconciling them against the party of twenty that set off from lincoln we have lost another five along the way luckily the akela group in essex had been watching for the departure from the east end and so we know that the full twenty set off along the thames in two groups often with eight arriving in swale and seven at ca new don the acrostic in the last telegram we intercepted spelled out the message at target rdf and iran that past my air ministry contacts who at last agreed to brief me on their concerns rdf stands for radio direction and finding i questioned this thinking it was an error and that they meant radio direction finding the navigation system we use but apparently this is something new from the boffins on the tizard committee they call it chain home and it refers to a new aeroplane detection system that uses reflection of radiowaves to range find as well as indicate bearing from air threats they have been experimenting with this for a while and are now building out a series of masts to give frontline warning of air attacks the first few stations are being built in norfolk lincoln and essex to provide a ring of defence around london and it looks like our spy c list friends are hunting for information about this technology it is not clear if they know what it is but it is certain that we have to stop them finding out i am also not sure what the missing party members are doing it cant be just more spying as their cover with the touring parties allowed them as much access as they were likely to get so something else is up i am hoping that the attached intercept will give usa clue we analysed the encrypted telegram and found that it uses a classic adfg vx cipher it uses the same keyword for the transposition stage of the cipher as i have used for this vi genere cipher and knowing that it should be reasonably straightforward to crack their message but you will have to check the details for yourself as i have to go harry has asked me to travel to caistor to setup a command post at the rdf tower in case we need to act quickly if we can crack this one and workout what is going on then i hope we can mount a counter to the spy c list operation before it succeeds pearl