Richter-Douglas agrees to the British proposal. He departs for Germany under cover of night, and the Brits make it look good by shooting him in the arm during his escape. When Geoffrey asks to see the hanger, you'd think the Germans would suspect something was up. York as Richter-Douglas is a hero who never really does anything heroic. He gets shot in the arm a couple of times, and in the most dramatic moment of the film, when he needs to decide where his loyalties lie, he faints.
Zeppelin fall down, go boom.
Geoffrey, for reasons unknown, is brought along on the LZ36 's first test flight, along with the Professor, his wife, Mary Ann, the Howells, etc. The zep performs admirably, but then the German intelligence officer on board commandeers the ship, ordering the crew to fly on a course for England. The plan is actually sucessful. Or maybe not. It's hard to tell whether it worked or not, because the movie just leaves that plot point hanging.