During the 1960s and 70s, many actors made a living on TV playing criminals, creeps and sociopaths. So, when you saw John Colicos or Nehemiah Persoff, you KNEW they were the bad guy...it was as simple as that! So, when "Secret of the Dunes" came on and I saw that Patrick O'Neal was in the show, I just knew he was playing some wicked scumbag...yet again. The same goes for Don Porter....he's also in the show and nearly always played evil in various TV shows...ditto for Frank Murth...and all three are in this episode.
The story begins in the desert. Some guy on a motorcycle oversees something some evil folks don't want anyone to see or hear...so they chase him down and murder him. And, as you'd expect, they make his death look like an accident. Barnaby Jones is hired by his wife to look into the case. However, the man he really wants to speak with is Charles Wheeling (O'Neal)...a very secretive and evil man who simply refuses to cooperate in any way. How can Barnaby proceed with the case if he can't even talk to one of his most important leads?
The plot to this is a bit like combining the later life of Howard Hughes with "The Most Dangerous Game"....and it makes for a very exciting story about a man so rich and powerful, there seems to be nothing the law can or will do to stop him. My only complaint is that the fiery finale was a bit poor due to the special effects...which weren't all that special. Still, a good episode and one that makes you wonder.