Daniela Bianchi's debut.
Edith Cérou's debut.
Françoise Rasquin's debut.
Pierre Bost, who had got ill, did not write a single line of the screenplay.
When John F. Carr was going through H. Beam Piper's letters years after his death, he found one which said: "I am now in the process of being divorced, if my future-ex-wife can ever get her French lawyers to get all the red-tape untangled. I suspect that she just doesn't know who to bribe. We are writing to each other again, in a very cordial and friendly manner. She reports that our red dachshund, Verkan Vall, of whom she retained custody when we split up, was in a movie, along with Bridgitte Bardot and Jean Gabin, a couple of years ago." The above can be found in the introduction by John f. Carr to the book 'Federation' by H. Beam Piper. There is a dachshund in the movie.