Englandspiel Details . The British Special Operations Executive ( SOE ) was sending Dutch intelligence agents into the occupied Netherlands during the war . As early as 1942 , the operation was penetrated by the German counter - espionage under Major Hermann Giskes of the " Abwehr " and continued under German control . Apprehended radio operators continued broadcasting encrypted messages , but without the required security checks , which should have alerted the SOE that they had been compromised . Further , SOE ' s head of codes Leo Marks claims to have quickly realised that , unlike all other coded messages , the Dutch messages contained no errors which made them indecipherable . He reasoned that this was because they were not coded in the field , but by German cryptographers . In the documentary " Churchill ' s Secret Army " he recounts how a wireless operator ended a telegraphic radio communication with " HH " , which stood for " Heil Hitler " and was the usual closing for German communications . The other party instantly replied " HH " which indicated it was a German who was used to doing it automatically and not a British agent who would have been confused by the two letters . Finally , he sent them a deliberate indecipherable message of his own , which was replied to . He reasoned that no ordinary agent could have reconstructed his message . He reported these findings to his superior who told him to not discuss the matter with anybody else and no action was taken . It was reported that agents who were supposed to return from the Netherlands had met with various calamities and so could not return . Further , in 1943 , two Dutch agents did manage to escape from captivity , but their claims on returning to Britain were dismissed ( and they were arrested for suspected counter - espionage ) due to a fake message sent by Giskes that two German agents were being sent to the UK from Holland . The operation was not completely shut down until Giskes himself sent a cynical clear text message to the SOE on 1 April 1944 complaining about the lack of recent business given that he had been servicing them for so long . Giskes ' message also " promised a warm welcome to any further agents SOE wished to insert into Holland " . By November 1942 it was clear to the signals section that agents were in German hands . The fact that neither the Dutch section , overseeing " operations " in Holland , nor other services were notified is probably motivated by inter - departmental rivalry . between the SOE and the rival Secret Intelligence Service ( " C " ) from which SOE had been created . Any failure would weaken political positions . It has also been argued that SOE had set up the operation for the single purpose of leading the Germans into believing that an invasion would take place in the Netherlands ( rather than Normandy ) . Similar allegations have been made about the fate of Francis Suttill and the SOE " Prosper " network in France . However , the decision to land at Normandy had not been made until late into the " Englandspiel " saga . Certainly Marks states in his book that he was ordered to deliberately withhold important cryptographic information from people investigating the Dutch operation at the time . Agents . During the " Englandspiel " the following people ( amongst others ) were dropped in the Netherlands : Aftermath . After the war , reproaches were made to the SOE for serious flaws in the preparation of the missions , and for ignoring warnings that agents had been caught , notably the absence of security checks , which were deliberate errors introduced into messages by the sending agent , the scheme for which was known only to the agent and the SOE . The security checks were supposed to indicate that the sender was the legitimate agent , and the absence of the checks should have told SOE that the agents had been captured and were reporting under duress . This was a serious violation of the SOE ' s own transmission protocol .