Ever since the Germans have been in Brussels there has existed an
"underground railroad" to aid escaped French and Belgian prisoners
of war in reaching the Holland border and thus regaining their lines.
The German secret service tried in vain to discover how the prisoners
got away, but without success--until last September. Then one of the
"operatives," as Detective Burns would say, conceived the idea of
donning part of a French uniform and appealing to Belgian farmers on
the outskirts of Brussels to help him to get over the frontier.
When a train load of French prisoners was moved from Lille to Aix la
Chapelle, this secret service man jumped from the train just before it
reached Brussels, and, taking refuge in a barn until dusk, appealed to
the farmer to let him remain there until he could obtain other clothes
to effect his escape.
Impressed by the spy's French language and uniform, the unsuspecting
farmer provided him with the desired garments. The spy then asked him
for the name of some one in Brussels who would help him. The farmer
directed him to a wealthy flour and feed dealer in the Belgian capital.
This man in turn passed him on to another Belgian who was connected
with the "underground railroad," and in less than two weeks the German
spy found himself in Rotterdam.
Of course he had learned the identity of every Belgian who had
befriended him, and on his return to Brussels he uncovered the entire
"underground" system. The trail led right to the chief surgical
hospital in the capital--the hospital in which Miss Edith Cavell was
the head nurse.