Lack of Moral Fibre

In late November 1943, Flight Engineer Christopher "Kit" Moran, DFM, refuses to fly to Berlin on what should have been the seventh "op" of his second tour. His superiors declare him "lacking in moral fibre," and he is sent to a mysterious DYDN centre.  Here, psychiatrist Wing Commander Dr Grace must determine if he has had a mental breakdown requiring psychiatric treatment -- or if he deserves humiliation and disciplinary action for cowardice.