Little Red Monkey plot
"THE IMPOSSIBLE CRIME"
A series of murders of nuclear scientists in London keeps Scotland Yard busy. These murders take place at about the same time as Bill Locklin, a special officer of the US State Department, attends the transfer of Professor Leon Dushenko. Dushenko is a Russian scientist who fled from the Soviet Union and they also wanted to attack him. Footprints of a monkey are found at the site of the attack. While Duskenko is secretly transferred to a nursing home, Locklin also goes after the hitmen, but is captured along with Julia Jackson, the niece of Scotland Yard Inspector John Harrington. Locklin is tortured to find out Dushenko's hideout.