It is the Jesus Franco that we like. Anticlerical one, the whom who tries to go beyond, destroying structures and making us see the world through distorted eyes. It’s the Jesus Franco who works with a low budget, the one that take care of the photography and direction but it’s not the one of masterpieces.
"Les Demons" is a Franco-Portuguese production of 1973, can be seen as the foundation of the most successful "Love Letters of a Portuguese Nun" of 1977.
Following the wave of "The Devils" by Ken Russell and reusing ideas of his own "The Bloody Judge" of 1970, the Spanish director, creates a quirky horror film with very erotic shades and especially with a highly anti religious moral.
A psychedelic photography as the direction and a pop/rock soundtrack that emphasizes the most important moments, accompany us on a story set in the middle Ages, and focused on the hypocrisy of the power.

The story is interesting and Franco tells it well, but the obvious limited budget creates many defects to the whole work. Willing and capable as ever, Franco tries to handle it as best, but not always he succeeds, wasting even a very interesting cast. The production limits often emerges and historical reconstruction, apart from costumes, is not always good. Also the plot suffers this but the end is good.
A witch burned at the stake launches an anathema against his three executioners: Lady DeWinter sadistic, bisexual lady who commands the nuns of a convent, the judge Jeffreys, the local squire who has power over all, Renfield a sort of loyal and lover of Lady DeWinter which does not hesitate to use is power.
 On these three corrupt and perverse characters but with a good facade strikes revenge Margaret's one of two daughters of the witch. The girl, took vows, receives the powers of Satan and magic lessons from an old witch who lives (could not be different) in the woods and eventually seduces and kills the three, reaching the highest point of eroticism in the Lesbos scene with Lady DeWries. At the same time, however, the innocent Kathleen sister of Margaret is accused and imprisoned for witchcraft, but then, with her sister is burned she take the legacy.

The beautiful Britt Nichols plays the diabolical Margaret, while Anne Libert, is Kathleen. The two plays very creating the appropriate characters for the goal of the movie. With them there are the ubiquitous Howard Vernon, (Malcolm DeWinter), Karen Field (the Lady) and Cihangir Gaffari in the role of Jeffreys.

Not a masterpiece and perhaps a bit 'disappointing if we consider that we are in the golden years of the Spanish director but for us is not to tear to shreds