Inspector Darrow investigates the death of a wealthy man.

The Office of Scientific Investigations tracks down the source of increased magnetism and radioactivity in Los Angeles, and discovers that a man-made isotope is consuming available energy from nearby mass every few hours, doubling its size in the process. Although microscopic, it will soon become big enough to destroy Earth; and how to stop it is yet to be determined. The film's Deltatron special effects footage is taken from the 1934 German sci-fi film GOLD.

In the days of King Henry IV, stalwart young Myles and his sister Meg have been raised as peasants, without any knowledge of who their father really was. But one day, they journey to Macworth Castle. There, Myles falls in love with Lady Anne Macworth, makes friends and enemies, and learns to be a knight.

An ex-tennis pro carries out a plot to have his wealthy wife murdered after discovering she is having an affair, and assumes she will soon leave him for the other man anyway.