The film was released in Italy and throughout most of Europe without experiencing any reported censorship problems, but was classified, prosecuted, and banned as a "Video Nasty" in the United Kingdom. Its theatrical distribution in the United States was delayed until 1984, when it was released in a heavily censored version under the title Unsane. In its cut form, Tenebrae received a mostly negative critical reception, but the original, fully restored version later became widely available for reappraisal. It has been described by Maitland McDonagh as "the finest film that Argento has ever made."
More killings occur. Tilde (Mirella D’Angelo), a beautiful lesbian journalist, is murdered at her home along with her lover. Later, Maria (Lara Wendel), the young daughter of Neal’s landlord, is bloodily hacked to death with an axe after stumbling into the killer's lair. Neal notices that TV interviewer Christiano Berti (John Steiner) appears to have an unusually intense interest in the novelist's work. At night, Neal and his second assistant Gianni (Christiano Borromeo) watch Berti’s house for suspicious activity. Neal decides to separate from Gianni in order to get a better view. Alone, Gianni watches in horror as an axe-carrying assailant brutally hacks Berti to death. But he is unable to see the murderer’s face. Gianni finds Neal unconscious on the lawn, having been knocked out from behind.
Giermani's investigation reveals that Berti was unhealthily obsessed with Neal's novels, and now that he is dead it is believed that the killings will cease. However, Bullmer, who is having an affair with Jane, is stabbed to death while waiting for his lover in a public square. Gianni is haunted by the thought that he had seen, but did not recognize, something important at Berti’s house during the night of the interviewer's murder. He returns to the house and suddenly remembers what was so important— he had heard Berti confessing to his attacker, "I killed them all, I killed them all!" Before Gianni can share this important detail with anyone, he is attacked from the back seat of his car and strangled to death.
Jane sits at her kitchen table when a figure with an axe leaps through her window, hacking off one of her arms. She spews gallons of blood over the kitchen walls before falling to the floor, the killer continuing to hack at her until she is dead. Neal is her murderer. Upon learning the details of Berti's sadistic murder spree, Neal had suddenly been overwhelmed by a forgotten memory involving Neal's murder of a girl who had sexually humiliated him when he was a youth in Rhode Island. The memory now constantly torments him and has inflamed his previously repressed lust for blood. Neal has become completely insane, and it was he who also killed Berti, Bullmer and Gianni.
When Inspector Altieri arrives at the house a few minutes after Jane's death, Neal kills her too. Later, Giermani and Anne arrive at the house in the pouring rain, and when Neal sees that he cannot escape, he commits bloody suicide in front of them. Anne runs outside to her car for a moment. Giermani relaxes and is suddenly murdered by Neal, who had faked his own death. Neal waits inside for Anne to return, but when she opens the door, she accidentally knocks over a metal sculpture that impales and kills the demented writer. The horror-stricken Anne stands in the rain and screams over and over again.
Although tenebrae/tenebre is a Latin/Italian word meaning "darkness" or "shadows", Argento instructed his cinematographer Luciano Tovoli to film the movie with as much bright light as possible. Shot on location in Rome, much of the film takes place during daytime, or in harshly overlit interiors. Except for the finale and some night scenes, the entire movie is shot with clear, cold light permeating the surroundings. Argento’s stated rationale for this approach was an attempt to approximate the allegedly “realistic manner of lighting” utilized in television police shows. The director explained that he was adopting "...a modern style of photography, deliberately breaking with the legacy of German Expressionism. Today's light is the light of neon, headlights, and omnipresent flashes...Caring about shadows seemed ridiculous to me and, more than that, reassuring." He also admitted that the lighting and camerawork used in Andrzej Żuławski's Possession (1981) greatly influenced his decision to have Tovoli shoot Tenebrae with such stark lighting.
For one of Tenebrae's main setpieces, the murder of the lesbian couple, Argento and Tovoli employed the use of a Louma crane to film a several minutes-long tracking shot that acted as an introduction to the sequence. The tracking shot, due to its extreme length, was fraught with potential problems and proved to be the most difficult and complex part of the entire production to complete. Patrick McAllister, writing as 'Ironwolfe' on Gerry Carpenter's Scifilm website described it as
Although an Italian production, the film was shot with most of the cast members speaking their dialogue in English in order to increase its chances for successful exportation to the United States. For domestic consumption, the film was dubbed into Italian. In the Italian language version, the killer's voice heard reading aloud from Neal's book in the opening sequence was supplied by Argento himself. In the English language version, Franciosa, Gemma, Saxon and Steiner all provided their own voices, while Nicolodi's voice was reportedly dubbed by actress Theresa Russell.
In the United Kingdom, the film was shorn of five seconds of "sexualized violence" by the British Board of Film Classification prior to its theatrical release. It later became one of the thirty-nine so-called "Video Nasties" that were successfully prosecuted and banned from sale in UK video stores under the Video Recordings Act 1984. This ban lasted until 1999, when Tenebrae was legally rereleased on videotape, with an additional one second of footage removed from the film (this version was also missing the previously censored five seconds). In 2003, the BBFC reclassified the film and passed it without any cuts.
The film has since been released basically uncut (minus approximately 20 seconds of extraneous material) on DVD in the US, allowing the film to be properly evaluated for the first time. Ed Gonzalez, of Slant Magazine, said that "Tenebre is a riveting defense of auteur theory, ripe with self-reflexive discourse and various moral conflicts. It's both a riveting horror film and an architect's worst nightmare. Keith Phipps, of The Onion's A.V. Club, noted "...Argento makes some points about the intersection of art, reality, and personality, but the director's stunning trademark setpieces, presented here in a fully restored version, provide the real reason to watch. Almar Haflidason, in a review for BBC.co.uk, opined, "Sadistically beautiful and viciously exciting, welcome to true terror with Dario Argento's shockingly relentless Tenebrae. Tim Lucas, in Video Watchdog, said, "Though it is in some ways as artificial and deliberate as a De Palma thriller, Tenebrae contains more likeable characters, believable relationships, and more emphasis on the erotic than can be found in any other Argento film."
Not all of the recent critical reaction to Tenebrae has been positive. Gary Johnson, editor of Images, complained that "Not much of Tenebre makes much sense. The plot becomes little more than an excuse for Argento to stage the murder sequences. And these are some of the bloodiest murders of Argento's career. In 2004, Tim Lucas reevaluated the film and found that some of his earlier enthusiasm had dimmed considerably, noting that, "Tenebre is beginning to suffer from the cheap 16 mm-like softness of Luciano Tovoli's cinematography, its sometimes over-storyboarded violence (the first two murders in particular look stilted), the many bewildering lapses in logic...and the overdone performances of many of its female actors..."
Flanagan observes that in Tenebrae, Argento offers two separate characters who suffer from impaired vision. Gianni (Christian Borromeo) is an eyewitness to an axe-murder, but the trauma of seeing the killing causes him to disregard a vital clue. Returning to the scene of the crime, he suddenly remembers everything, and is promptly murdered before being able to tell a soul. Homicide Detective Giermani reveals that he is a big fan of the novels of Agatha Christie, Mickey Spillane, Rex Stout, and Ed McBain, but admits that he has never been able to guess the identity of the killer in any of the books. He is similarly unable to solve the real mystery until the last corpses are piled at his feet—he cannot see Peter Neal for what he really is.
Neal, who ultimately responds to an ongoing series of murders by becoming a killer himself, emphatically introduces the theme of impaired vision when he admits to Giermani: “I've tried to figure it out, but I just have this hunch that something is missing, a tiny piece of the jigsaw. Somebody who should be dead is alive, or somebody who should be alive is already dead.” Of course, Neal himself is the “missing piece”, and in the end he will fake his suicide and become the “somebody who should be dead.”
McDonagh notes that Tenebrae expands a theme already introduced in Argento’s earlier giallo films. "The Bird with the Crystal Plumage, The Cat o' Nine Tails, Four Flies on Grey Velvet (1972), and Deep Red are full of sex, of course: transvestitism and sexual role playing are in all four films central factors and none lacks for imagery dealing in diverse sexual behavior. But Tenebrae’s overall sensuality sets it apart from Argento’s other gialli.” She says that the film’s sexual content and abundant nudity make it “the first of Argento’s films to have an overtly erotic aspect,” and further notes that “Tenebrae is fraught with free-floating anxiety that is specifically sexual in nature.”
Flanagan and McDonagh – and, indeed, most critics – have noted that two sexually charged flashbacks are key to understanding Tenebrae. These distinct but strongly related memory fragments are introduced repeatedly throughout the course of the film, usually immediately following a murder sequence. Although these flashbacks are never fully explained, the first of these memories reveals a beautiful young woman’s sexual humiliation (basically, an oral rape) of a teenaged boy (presumably Peter Neal) on a pale-white beach, followed (in the second flashback) by the vicious revenge-murder of the woman some time later. The young woman (played by transgender actress Eva Robin's) is mostly topless during this first sequence, and she humiliates the young man by jamming the heel of one of her Freudian shiny red shoes into his mouth while he is held down by a group of gleeful boys. McDonagh notes that all of the fetishistic imagery of these flashbacks, combined with the sadistic details of the murder sequences in the main narrative, “set the parameters of Tenebrae’s fetishistic and fetishicized visual vocabulary, couched in terms both ritualistic and orgiastically out of control…Peter Neal indulges in sins of the flesh and Tenebrae revels in them, inviting the spectator to join in; in fact, it dares the viewer not to do so.”
McDonagh notes that Argento also emphasizes a similar doubling between Neal and Giermani. "Giermani...is made to reflect Neal even as Neal appropriates his role as investigator...the detective/writer and the writer/detective each belittles his other half, as though by being demeaned this inverted reflection could be made to go away." McDonagh also observes that, in what is arguably the film's most potent shock, Neal at one point really does make Giermani "go away", virtually replacing him on screen "in a shot that is as schematically logical as it is logically outrageous."
While rejecting this thematic concern as unrealized by Argento, McDonagh noticed that the result of the director’s experiment is a strange “architectural landscape” that becomes the “key element in differentiating Tenebrae from Argento’s earlier gialli.” Argento’s use of unusual architectural space and so-called visual “hyper-realism” results in an enormously fake looking environment. Seizing on the director's additional comment, “…I dreamed an imaginary city in which the most amazing things happen”, she notes that the film’s “fictive space couldn’t be less 'real'…Its imaginary geography is pieced together out of fragments of 'Rome'…that emphasize vast unpopulated boulevards, piazzas that look like nothing more than suburban American malls, hard-edged Bauhaus apartment buildings, anonymous clubs, and parking garages.”
McDonagh argues that Argento’s influences for Tenebrae were far broader than just his own films or previous Italian thrillers. She notes that the film’s “surprisingly strong narrative” is suggestive of “the most paranoid excesses of film noir.” McDonagh suggests that Fritz Lang’s Beyond a Reasonable Doubt (1956) (‘in which a man convicted of murder on false evidence…is in fact guilty of the murder”) and Roy William Neill’s Black Angel (1946) (“in which a man who tries to clear a murder suspect does so at the cost of learning that he himself is the killer”) both utilize such a similar plot twist to Tenebrae that Argento may very well have used them as partial models for his story .
Douglas E. Winter has opined that Tenebrae’s Louma crane sequence was stylistically influential and was specifically “replicated in Brian De Palma’s The Untouchables (1987).” In Raising Cain, De Palma’s “surprise reveal” of John Lithgow standing behind a victim is often discussed as being an unacknowledged “steal” from Tenebrae. Robert Zemeckis’s What Lies Beneath (2000) also contains a very similar moment, although Zemeckis has denied having any familiarity at all with Italian thrillers.
Argento had used the Italian rock band Goblin to provide the musical scores to two of his previous films, Deep Red (1975) and Suspiria (1977). The group had disbanded in 1980, but three of the band's members—Claudio Simonetti (Roland Jupiter-8, Roland Vocoder Plus, Minimoog, Piano, Electric piano, Oberheim DMX Digital Drum, Roland TR-808, Roland MC4 Computer), Fabio Pignatelli (Fender bass normal and fretless), and Massimo Morante (Electric and Acoustic Guitar)—reunited at Argento's request to work on Tenebrae. The resulting synth-driven score was credited to "Simonetti-Pignatelli-Morante".
While not as well regarded as Goblin's earlier scores for Deep Red, Suspiria, or Dawn of the Dead (1978), Tim Lucas felt the soundtrack is "...so fused to the fabric of the picture that Tenebrae might be termed...a giallo musicale; that is, a giallo in which the soundtrack transcends mere accompaniment to occupy the same plane as the action and characters."
The Tenebrae soundtrack album has been enduringly popular enough to have had multiple reissues in numerous countries since its original release in 1982 on the Italian Cinevox label. That version consisted of only eight tracks. In 1997, Cinevox issued a greatly expanded version on CD, including eleven bonus tracks, with a running time of over an hour. In 2004, the expanded CD was released in the U.S. on the Armadillo Music label.
On the DVD review website, DVD Times, Michael McKenzie argues that the film's actual title is Tenebre, since it is that title that was "used for the Italian prints and the cover of the US DVD. But another DVD Times reviewer, Michael Brooke, takes the opposite view, stating, "...the box says Tenebre, but the title that actually appears on screen (both on the film itself and the trailer) is Tenebrae, which is in fact the title under which this 1982 Dario Argento film was released in Britain, and indeed the title under which it was accused of being a "video nasty" in the moral panics that engulfed the country...