This film is loosely based on Cornell Woolrich's novel, The Bride Wore Black.
The film's opening credits state that it is based on "a novel by David Khune" which is an alter-ego for director Jesús Franco.
Final film of Ángela Tamayo.
Irma Zimmer takes Nadia to a place where she is living, under her persona of "Joan S. Bermann". The prominent sign on the door, shows her name between "A. Labartin - corsets" and "M. Saffra - paintings by hand" - this being the name of one of the film producers, Michel Safra.