|The Fiendish Plot of Dr. Fu Manchu: Fu Manchu's 168th birthday celebration is dampened when a hapless flunky spills Fu's age-regressing elixir vitae. Fu sends his lackeys to
round up ingredients for a new batch of elixir, starting with the Star of Leningrad diamond, nabbed from a Soviet exhibition in Washington. The FBI sends agents Capone and
Williams to England to confer with Nayland Smith, an expert on Fu. Nayland suspects Fu will kidnap the king and queen and demand the George V diamond as ransom.