Desperate, sensing defeat, the Nazis resort to crippling reprisals against civilians, sustained surveillance and counterespionage. Then comes the Battle of Arnhem. Panic-stricken, the Germans redouble their efforts to stamp out local resistance. A "double agent" discovers the hideout in the swamp. Tense, anxious moments follow. Will he succeed in betraying the refugees to the hated, dreaded Secret Police. . .?