Diana Lorys is Anna, a nightclub dancer, who meets Cincia (Colette Jack), who invites Anna to her home. Cincia tells Anna that her talent and beauty are above and beyond where she is working and makes a vague promise to Anna that she can make her a bigger success. Anna agrees and soon finds comfort in Cincia's home. A local doctor, Paul (Paul Muller), is eventually summoned to Cincia's home under the assumption that Anna is ill. Apparently, Anna has been having nightmares--those of her killing people or waking up not knowing what she has done, with someone dead in her bedroom.
Les cauchemars naissent la nuit is, as a mystery, reminiscent of Umberto Lenzi's Orgasmo (Paranoia) (1969) in the respect that Anna's reality is being manipulated by those around her. Anna's subsequent madness is borne from this manipulation. The key figure in this manipulation would have to be Colette Jack's Cincia, but during the nightclub sequence when Cincia first sees Anna, it would appear that Anna actually seduces Cincia. Anna's striptease sequence is shot in Franco-style (aka very lovingly) (aided by José Climent's photography and a sexy score by Bruno Nicolai); and it almost seems that Cincia is compelled to have Anna in her home.
Lorys's Anna remains the focus of Les cauchemars naissent la nuit, and this makes it difficult to discern what is going on around her. Franco shows many an emotional scene where Anna wants to flee Cincia's home, and Anna often runs into the arms of Muller's Paul. She continually asks for help. Paul, not uncaring, lends a sympathetic ear, yet his ultimate advice is often just "go home and rest."
More telling perhaps about Les cauchemars naissent la nuit is where this falls in Jess Franco's filmography: it is only slightly removed in time from his previous Eugénie (1970); and his subsequent film would be Christina, princesse de l'érotisme (1971). It is very easy to see Les cauchemars naissent la nuit as an experimental, transitional film: Les cauchemars has the intense subjective sexual obsession of Eugénie combined with the ethereal, almost random, characters of Christina. Jack Taylor appears late in the film as one of Cincia’s lovers; and when Anna and Taylor’s character interact, it is often composed of poetic, playful dialogue. Taylor’s character doesn’t seem real, and if he’s helping Anna, then it is very cryptic. Finally, giving a very precious appearance in a small performance is Soledad Miranda as a beautiful girl peering out of a window across the street from Cincia’s house. She has dreams that she shares with her lover of coming into a lot of money (this is important to the plot?). Miranda is dead sexy--Franco composes her primarily nude wearing only thigh-high boots. Franco had an intense obsession for Miranda, and it undoubtedly shows.
Les cauchemars naissent la nuit is a lithe, meandering, arty, poetic film. I tend to prefer my cinema like this--a film which has really nowhere in particular to go in terms of story, so its imagery becomes prominent and, in the case of Franco, seductive. A minor entry, perhaps, in Franco’s filmography, because of the films preceding and following it. However, here’s some facts to conclude this post taken from essential Obsession: The Films of Jess Franco:Only released in Belgium, this variation of the Miss Muerte story (a nightclub dancer unconsciously commits murders for somebody controlling her) has become virtually invisible since this limited release. Franco used the same story three years later for his own production of Los Ojos Siniestros del Dr. Orlof. Local critics writing about Les cauchemars naissent la nuit found that “the vague screenplay in the crime novel vein was only a pretext for showing scenes of a dubious nature with excessive nudity.” It is also true that Belgium is probably the most prudish country in Europe: even sex magazines are sold with stickers to cover genitalia! When asked (in Vampirella n° 13) what had been his smallest budget to date (in 1973) Franco named this film.
(from Obsession, ed. Lucas Balbo & Peter Blumenstock, Graf Haufen & Frank Trebbin Publishing, Munich, Germany: 1993, p.77)
Les cauchemars naissent la nuit has been released by Media Blasters/Shriek Show on DVD as Nightmares Come at Night. Also, check out Aaron’s review at his killer blog, The Bone Throne.
Jess Franco's Sexy Sisters (1977) is one of a baker's dozen (or so) films that Franco made for Swiss producer, 
Sexy Sisters begins visually and thematically in classic Franco style: dreamy, disorienting, and hypnotic. The opening floorshow and the odd, contrived sequence of events leading Joe into Milly's "quarters" are fantastically over-the-top. Franco familiar-face, Jack Taylor's appearance is welcomed, and his initial sequence with Gambier's Milly is fun. Taylor brings as much reservation to his role as he can muster (presumably to keep from laughing), while Gambier is totally uninhibited on camera. In fact, Gambier steals all of her scenes within Sexy Sisters and her presence would merit a viewing of the film alone. While the substance of Franco's compositions is wild in the Franco way, his camera is static. Dietrich is later asked in the same interview in Obsession whether he would work again with Franco, today. Dietrich would but says he would not let Franco shoot his own films. Likewise, Dietrich didn't let Franco shoot Sexy Sisters (
Sexy Sisters begins a dark and provocative tale. Edna and Milly are true adversaries in the guise of caregiving Edna and pitiful and sick Milly. Edna's elaborate seduction of Joe is revealed to be passive-aggressive torture of Milly. Later, Edna has sex with her maidservant behind the bars in front of Milly with a wicked smile on her face. Later, Edna invites another man over to the villa to have his way with Milly (but this time, he's someone from Milly's past whom she hates very much). Taylor's diagnosis of Milly developing paranoid schizophrenia is fueled by Edna's deeds. Taylor's character thinks Milly's escapades are hallucinations that she is truly believing are real. Edna is doing nothing to dissuade the doctor. Why? The answer to that question comes with the final two-thirds of the film, as Sexy Sisters descends into a tired, formulaic, and predictable plot. Sexy Sisters becomes totally unengaging on a narrative level (and Franco's powerful, discursive visuals are absent to supplant the narrative). Franco is able to steal the occasional flare, but he's hampered by too much of a seeming desire to make a typical softcore film. It doesn't help either that virtually all the male actors, save Taylor, give absolutely atrocious performances. Stanford and Gambier are the real stars here and are shouldered with delivering Sexy Sisters with nearly all of the film's energy. As it stands, Sexy Sisters is completely uneven, undoubtedly entertaining and engaging at times, and truly overshadowed by myriad Franco films in his diverse filmography.
Not having a fondness for writing plot synopses and frankly believing I am completely unable to do so here, I will forgo even attempting writing one. Interestingly and unsurprisingly, Franco had "virtually no script" for Succubus (Necronomicon) and would write dialogue scenes the night before shooting, while in the morning star 
The opening sequence is powerful. Reynaud's Lorna, brandishing what seems a riding crop, comes out of darkness to encounter a bound female and male, both scantily-clad in tattered bits of clothing. She has her way with the two. A pervasive feeling within the scene, although the two look raggedy and bound intentionally, it seems the two are willing captives, seduced by a powerful sensuality. Jack Taylor, as William, comes home to his apartment, after a night's drinking at the cabaret, where's Reynaud's opening was revealed as a performance. Mysterious Lorna is waiting for him and the two go to bed. These two opening sequences are mirrored at the end. Mysterious Lorna is still in William's apartment when he gets home (to his surprise) and she takes him into his arms. Lorna performs her act as a rehearsal, just before this scene, which ends when another power takes over Lorna (possibly someone whom she is under control? The film dissolves time to time into the eyes of a character, beckoning to her). 
Symbolism is pervasive throughout Succubus with a heavy emphasis on the meta aspect of capturing female imagery. Gorgeous Lorna seduces a beautiful young blonde woman (again, seduced or willing lover is unknown) in a scene littered with mannequin models which Franco places side by side his female characters. All of the characters in Succubus are drawn to Lorna: she has two encounters where strangers approach her whom Lorna denies knowing; the people in her life, like William, are extremely possessive of her; and there is possibly one character who is controlling Lorna in a mystical or supernatural way. Ultimately, Succubus is a film about a desire to capture and possess the female spirit, despite making any true attempts to understand or accept it. A beautiful-looking film, I was entranced during its whole running time.
All objective facts about the production, save the quote from Fritz Lang, are taken from Cathal Tohill and Pete Tomb's extremely essential film book,