General von Klinkerhoffen thinks that a mixed marriage between a Frenchwoman and someone from the occupying forces would provide a good propaganda piece for the newspaper. He decides that Captain Bertorelli should marry Edith. A party is arranged at the château so that local dignitaries can meet the 'happy couple'. The Resistance rescues the airmen from the château via an underground river. The airmen end up stuck in a sewer underneath the town centre. (thetvdb.com)