It is late 1940 and the Nazis have been
occupying Paris since early summer of that year. The city is becoming a
favourite posting for senior Nazis including a large number of the group
known as the "Dark Knights" who organised the underground Olympics in
1936. Although their champion Helga was defeated in
that event, the group still strongly believe in the physical superiority
of the blonde Aryan woman over women of other non-Aryan races.
They call this belief the "Brünnhilde Principle" after the valkyrie
shieldmaiden of Norse mythology.
So one evening Dark Knights assemble to prove their theory with a fight
between their ideal Aryan woman and a member of a non-Aryan race.