The Germans do a bombing run and when a collapsed building is combed, a man is found with a knife in his chest. It appears that he was not killed in the explosion but rather, murdered. His wife admits to having had an affair. She is filled with guilt. Meanwhile, Foyle's son, a pilot for the RAF, instead of getting his own assignment to fly into battle is put into a test pilot program, using experimental jets. The problem is that while he is doing this heroic work for the war effort, he can't tell anyone what he is doing. As a matter of fact, he comes under suspicion for spying (this, of course, is not true, but he is being vilified by some overzealous brass). The effort to explain the stabbing and the incarceration of his son become the two principle problems Foyle must deal with. There are levels of authority that must be dealt with and, of course, they are unyielding in their tunnel vision way. A separate issue has to do with the shortsightedness of a minister father, trying to diminish the importance of the young woman who is Foyle's driver. I liked this episode.