The plot to "A Knowledge of Astronomy" is one of the more unusual ones for "The Public Defender", though it is interesting.
The story begins with some guys fighting over a card game and one of them gets bashed over the head for cheating. Soon after, in a seemingly unrelated case, a driller is arrested for stealing drill bits...something which seemed as if he was set up. But how do the card game and a knowledge of the stars all work together to help Bart Matthews solve this case and help his wrongly accused defendant?
The episode includes Matthews hiring a private detective (Hugh Beaumont) to pose as an oil field worker. I have no idea if any public defender office ever hires private dicks....perhaps they do though it seems unlikely. Regardless, it's a complex but enjoyable plot and the episode certainly is one of a kind!