[1] The film is based on a novel called "Francisco" by Anselmo Suárez y Romero where he makes a socio-economic analysis of slavery and class struggle.
It also offers a critical analysis of the novel, showing how the author's social background led to his use of particular dramatic structures to convey his liberal, humanitarian viewpoint.
While the second approach only broadens the story’s scope in a Marxist critique that includes an uglier version of slavery that was ignored by the author.
The film starts off with the perspective of Anselmo Suárez y Romero's original novel, Francisco was sold at the age of 10 but was taught how to read and write by the head mistress of the sugar cane plantation named Senora Mendlzabal.
The two quickly fell in love and Francisco pleaded to Senora to marry Dorota a multitude of times but was constantly denied.
They're secret love was discovered by Senora however and was quickly put a stop to by whipping Francisco and moving Dorota to work for a Frenchmen for a time.
This story landed Francisco into working in the fields hours on end by an overseer and commanded by Senora's son named Ricardo who has a secret attraction to Dorota.
The film has an interview with the author of Angelo Suárez y Romero that goes on to explain on why he written the story of a love triangle instead of the tragedy of being a slave.