The best James Stephenson’s mystery movies

After a woman shoots a man to death, a damning letter she wrote raises suspicions.

Philo is in Vienna working for the US Government to see if Archer Coe is selling aircraft designs to foreign powers. He grabs the plans with Archer's signature, but is captured by police before he can escape. Deported he comes back to America and plans to confront Archer, but Archer is found dead in his locked bedroom with a gun in his hand. While it looks like a suicide, Vance knows better and the coroner finds that Archer has been shot, hit with a blunt instrument and stabbed - making suicide unlikely. But Vance is on the case and is looking to see if government secrets have been sold and who has murdered Coe. This is a remake of "The Kennel Murder Case" using aircraft designs and espionage instead of Chinese porcelain and dog shows.

Nancy Drew and Ted Nickerson solve a kidnapping case of a wealthy elderly lady. Ted has to disguise himself as a nurse while Nancy becomes a "widow" in order to locate the lady they are rescuing.

Greedy diamond mine owner Eli Snedeker, resentful that his ex-foreman John Gamble stopped him from taking over kindly, but drunken, mine owner Roger Smythe's mine just as he was about to strike it rich, kills Smythe and blames it on Gamble. Grabbing the diamonds, Gamble flees Africa to England where he changes his name and begins a new life. What he hasn't counted on, though, is meeting and falling in love with Smythe's daughter Katherine, who falls in love with him but can't marry him until she can deal with her hatred of John Gamble, the man she believes killed her father.