"Oh, you need not worry," replied Dawson serenely. "Your letters were quite innocent. I am gratified to learn that your two sons in the Service are happy and doing well, and that you contemplate the publication of another book."
It was impossible not to laugh at the man's effrontery, though I felt exasperated at his inquisitiveness. After all, there are things in private letters which one does not wish a stranger, and a police officer, to read.
"And how long is this outrage to continue?" I asked crossly.
"That depends upon you. As soon as I am satisfied that you are as trustworthy as the local police and other authorities believe you to be, your correspondence will pass untouched. It is of no use for you to fume or try to kick up a fuss in London. Scotland Yard would open the Home Secretary's letters if it had any cause to feel doubtful of him."
"You cannot feel much suspicion of me or you would not tell me what you have been doing."
"You might have thought of that at once," said Dawson derisively.
I shook myself and conceded the round to Dawson.
"It has been plain to us for a long time that the food parcels despatched by relatives and 'god-mothers' of British prisoners in Germany were a possible source of danger, and at last it has been decided to stop them and to keep the despatch of food in the hands of official organisations. Since there are now some 30,000 of military prisoners, in addition to interned civilians at Ruhleben, the number and complexity of the parcels have made it most difficult for a thorough examination to be kept up. We have done our utmost, but have been conscious that there has existed in them a channel through which have passed communications from enemy agents to enemy employers."
"I can see the possibility, but a practical method of communication looks difficult. How was it done?"
"In the most absurdly simple way. Real ingenuity is always simple. I will give you an example. An English prisoner in Germany has, we will suppose, parents in Newcastle, by whom food has been sent out regularly. He dies in captivity, and in due course his relatives are notified through the International Headquarters of the Red Cross in Geneva. He is crossed off the Newcastle lists, and his parents, of course, stop sending parcels. Now suppose that some one in Birmingham begins to send parcels addressed to this lately deceased prisoner, his name, unless Birmingham is very vigilant, will get upon the lists there as that of a new live prisoner. The parcels addressed to this name will go straight into the hands of the German Secret Service, and a channel of communication will have been opened up between some one in Birmingham and the enemy in Germany. Prisoners are frequently dying, new prisoners are frequently being taken. Under a haphazard system of individual parcels, despatched from all over the British Isles, it has been practically impossible to keep track of all the changes. For this, and other good reasons, we have had to make a clean sweep and to take over the feeding of British prisoners by means of a regular organisation which can ensure that nothing is sent with the food which will be of any assistance to the enemy."