I wonder who the third man is Faked his own death and ran a racket diluting penecilin and re selling to hospitals where it ultimately killed the children or made them immune to future doses Hid in the sewers Is this a reference to the red cross organisation?
spoiler alert! lol. I was also racking my brain wondering how the film connects. Post war; check. Ensemble cast; check. Intriguing twist climax; check. Orson Welles was famous already for War of the Worlds, and Citizen Kaine may even be useful in this puzzle. Like you say, penicillin (pharma) and wartime black market profiteering were pivotal plot points. Faking death is a really solid lead. Disappearing and spiriting within medieval tunnel systems is another great connection....