One of the few episodes where the Germans shoot at the POWs. Even more rare, they fire back (Corporal Newkirk/Richard Dawson is seen returning fire on the Germans).
When the doctor and Hogan's gang, dressed like Germans, enter the building and walk down the hall, the hallway is part of the Star Trek (1966) set. That hallway was used many times in the Star Trek (1966) series and a few times on Mission: Impossible (1966). All three shows were filmed at Desilu Studios.
Karl Bruck and Bard Stevens made guest appearances in this episode. They also made guest appearances together as Underground agents in Klink's Masterpiece (1970).
This was Curt Lowens only guest appearance in the series.