Brown was one of the prisoners sent to Freigegeben (Open Prison) Stalag III-D for an initial examination. A former member of the British Union of Fascists, he had developed a good relationship with the Germans, which he exploited to run a very efficient blackmarket operation among the conscripted foreign workers, using some of the profits to buy "luxury" items such as extra food, medicine for the camp hospital and even musical instruments for the camp band. Brown also had a hidden radio so was aware of the course of the war.