The Descent, a 2005 British film, directed by Neil Marshall, is a genuinely frightening experience.

The plot is simple, a group of women get trapped in an uncharted cave, and discover a group of cannibalistic underground monsters while looking for an exit. The main conceit of the movie, its claim to originality, is the fact that horror happens underground, in a constrained and dimly lit space. What could have been a gimmick quickly proves visually and thematically fruitful, as the choice produces a slew of effects which enrich the horror tropes. Thematically, the film is close to Deliverance – a comparison made by several reviewers at the time – in that it foregrounds the connection between the environment and the monsters it generates. Or to put it differently, the environment is the real monster of the fim. Indeed, the beginning of the cave’s exploration, which merely presents caving as a trip towards frighteningly regressive regions, is the most convincing part of the film. The opening sequence, during which the heroine’s family dies in a brutal car accident, establishes a narrative contract in which anything can happen, even the sudden death of a cute child. Together with copious foreshadowing regarding the dangers of cave exploration and – less efficiently – with copious startling false alarms, the narrative strategy calls our attention to the threat inherent to the sport.

A most disturbing and effective sequence involves the group of women crawling through a narrow corridor, which eventually collapses.
 

 
Marshall shows us all the women going through the narrow passage until the heroine, Sarah, panics and causes the tunnel to collapse. Repetition is key here, and the tension increases with each woman, precisely because nothing alarming happens. The device conveys the feeling that the cave is threatening not because of what could happen but because of its very existence. The continuous presence of the environment is in itself a source of danger, even while the violent discontinuities of the horror genre have not appeared yet. Besides, in this case, the apparently unmotivated repetition of similar actions – it is even hard to tell who is crawling through the tunnel at a specific time – has a faux-naturalistic quality which may recall the tactics of the popular “discovered footage” films, and their attempts to imbue horror with a highly codified form of realism (cf. David Bordwell’s recent and insightful comment on the form).

Formally, the cave-setting also has interesting consequences in that it frequently functions as a form of cache or mask, as vast areas in the frame are entirely black, maintaining an ambiguous spatial relations to the locus of action. This distinctive effect – a pre-modern cinematic device naturalized by the setting here – not only produces unusual images, but it also works to open potential spaces for horror, potential startles. Genre connoisseurs expect startle effects and are acutely aware of the need to observe dead spaces. In The Descent, this is countered by the impossibility to see though these spaces.
 

 
The end of the film suffers, from the fact that the tension between naturalized scary effects and identifiable genre conventions is abandoned in favor of an overt formula. Plausibility issues also interfere, as the blind monsters have developed an acute sense of hearing but apparently no sense of touch. Several close escapes thus appear artificial and disruptive to the narrative contract, even though they may be thrilling self-contained moments. A scene during which a monster walks on a motionless Sarah without noticing her presence is a striking example. The ending of the film is not without pleasures, but these are referential pleasures, tied to knowledge of the codes and the history of the genre, a pre-condition to appreciating the minor deviations on display. Will there be a final girl? Will our point of focalization turn out to be the heroine after all? The issues at stake towards the end of the film are far removed from any involvement with the characters. Still, the gorgeous photography sustains the film even in its weakest moments.

My viewing experience, however, was shaped long before this final inflection by the opening sequence of the film. There are several possibilities open to horror film-makers, but an usual gambit is to open with a quiet, lustful act, with hints of the horror to come included in the mix: the auto-stopper in The Texas Chainsaw Massacre, the explanatory text in Cloverfield,  the hints of madness in The Brood, the sport and shower scene in Carrie, etc. The Descent initially seems to adopt this strategy of introducing harmless scares before the actual monsters enter. The film opens with a rafting scene, fraught with tension and the suggestion that rocks or water could severely harm one of the female protagonists – a fitting introduction for the speleological horror expected by most viewers at this point – which ends in satisfied displays of camaraderie.

The thrill ends quickly, however, and Sarah, one of the girls, leaves a bit early to come home with her child and husband. This initially appears to be a bridging scene meant to accompany the credits, an introduction to a meaningful conversation or perhaps a naturalistic account of a change in location. The scene is a bit long, though, and after twenty seconds, you realize that the film is dedicating a portion of its running time to showing us an “intermediary space”, “un espace intermédaire”.
 

 
These empty places, in which you “leave the realm of the expected meanings” (Jean Cleber) are of course ubiquitous in our lives, but notably absent from the compressed narratives of mainstream cinema. You expect them in Duras’s films, but not in a fairly low-budget genre work. Foregrounding these spaces is the strategy used in Jarmusch’s Broken Flowers or Sofia Coppola’s Lost in Translation, and it serves to establish these two films as flamboyantly non-generic. This is also what Nicolas Winding Refn used so effectively in Drive, but then, Drive is a film about style and film-making more than a genre exercise. The very logic of genre and commercial cinema dictates that scenes must have a narrative or thematic significance. For a fleeting moment, The Descent seems to forego that logic and open itself to a whole realm of possibilities. If a genre is a set of possibles, a specific “vraisemblance” meant to frame our expectations (Jonathan Culler) then this aimless conversation challenges our notion of genre.

Then comes the tell-tale shot:
 

It lasts for eight seconds, after a series of much more classical close shots on the three protagonists. The unusual camera placement calls our attention back to the presence of a photographer and a director. This is a shot with a narrative purpose: it suggests the need for Marshall to establish a coherent sense of space, the need to organize the scene and to provide it with a form of order. The shot does not in itself appear clearly teleological, but it suggests very strongly that something is at stake, that the fleetingness of the scene has to give way to a usable set-up.

Indeed, that set-up is used only a few seconds later, when a gruesome car accident kills both Sarah’s husband and child, reframing our expectations once more towards a shock-based filmmaking. When a slow-motion shot shows us a metal tube perforating the husband’s head, any trace of generic ambiguity is gone. Shock and gore erase the fleeting moment of uncertainty to reassert generic conventions. These remain somewhat blurred for a while in the film as the formal qualities of the cave environment threaten to take over the narrative imperatives of the genre, but they never truly go away.
 

 
For a brief moment, The Descent offers a tantalizing glimpse of another film, a possible naturalistic character study centered on a family in dangerous places. That way only remains open for a few seconds in the film, but it leaves a lasting impression. Its openness points to richness of possible narratives which suggest that the characters are not mere cannon fodders, that they are not entirely constrained by the fairly rigid boundaries of a horror-driven tale. Simultaneously, it asserts the film-maker will to knowingly work in the genre, having examined other possibilities only to discard them.

The scene therefore works not only as a repetition for later sequences, but also as a miniature of the film’s structure: openness and promises violently brought back to the specific pleasures offered by genre conventions. The Descent may not be the most accomplished horror film in the Western canon. It is a smart and efficient movie, which puts forward its affection for the conventions it puts to use. It may, however, lead us to regret the many ways not taken, and the promises they held.