It has been a while since I've read Jacques Derrida's Specters of Marx, but watching The Devil's Backbone (2001) strongly reminded me of some of the arguments Derrida makes, and the way he talks about the simultaneously present and non-presents of hauntology. Derrida is generally referring to political, and perhaps philosophical, movements or revolutions - arguing that after their timeliness has come to pass, they still affect future thought via hauntings, echoes, or traces (Marx may have died, but Marxism is all the more important for it).
In my reading of Specters of Marx, the 'present' of the 'non-present' is established via the circulation of language and thought - so that while a particular revolution may be over, it affects future movements each time it is 'invoked' or reiterated in discussion. For Derrida, this 'invoking' is a serious issue. He begins Specters of Marx with a reading of Hamlet, where Hamlet repeatedly invokes the ghost of his dead father by calling out to him, and later by swearing Marcellus and Horatio to secrecy. The swearing works as a sort of agreement: first, to not speak of the ghost, but as a result, also that the ghost exists.
The Devil's Backbone takes place during the Spanish Civil War and centers around an orphanage where most of the residents have lost their parents in the war. The adults running the orphanage repeatedly refer to 'the cause,' and have a stack of gold that they use to support the Republicans. It appears that most of the orphans were orphaned as a result of their parents playing the role of 'freedom fighter' for the Republicans. This is significant later in the film, when we see several characters associated with the orphanage executed by Nationalists, and also in terms of the final outcome of the film (which is decidedly Marxist in sort of 'Lord of the Flies' way).
While the war continues on around them, the orphans seem to be more concerned, however, with the ghost of Santi that apparently haunts the orphanage. Santi is interesting, because he exists in this liminal space of (non)presence, where it is difficult to determine if he has some sort of real, material affect on the other characters in the narrative (the other orphans). Here we see the protagonist Carlos reach out and take a hold of blood that floats up away from the ghost whenever he appears:
Carlos is actually able to drag down some of this 'blood' out of the air, suggesting that the ghost is a material entity. This is, of course, the only time we actually see a character touch the ghost, though later he does, apparently, rattle some cabinets.
Now, the metaphysical consideration of a ghost's materiality is not what is really interesting here though. As the film continues, we learn that the ghost actually wants something from Carlos: to help him seek revenge by helping the ghost kill his killer, which it turns out, is the reason for the ghost haunting the orphanage. The revenge, however, is complicated. The ghost does not want Carlos to kill the one that murdered him, but instead bring him to the place where he was murdered so that Santi, with all his quasi-materiality, can seek revenge. While the viewer might be left to wonder about the metaphysical reality of the ghost, we now understand that the central issue is not necessarily how the ghost will kill the killer, but how Carlos and company will bring the killer to Santi's grave.
A clear conflict emerges in the end of the film, the orphans against the gold-thiefs (including Santi's murderer). When rallied to fight by Jaime, the bully and sometimes-leader in the film, a younger boy says: "But they have the file. And they are bigger than us, stronger." Jaime's replies: "Yes, but there's more of us." While clearly an allusion to the struggle of the proletariat of Marx, what I'm really interested in here is how this initiates a movement in the film, which directly contributes to how the 'specter' of Santi operates. Once rallied, they are enlisted in the specter's cause, and work together to draw the murderer to the site of the murder as per Carlos's mission. Once they do so, together they attack the killer with homemade spears:
The boys do not, however, spear the murderer to death. Instead they, according to the desires of Santi, push him into Santi's grave, which is the pool you see in the background of this image. The gold-thief is weighed down by the gold in his pockets. Unable to swim, he quickly tries to remove the gold in his pockets, but Santi shows up just in time to make sure that does not happen. The message in the film seems clear though: while Santi orchestrated these events, he did not necessarily have to ever physically play a role - Santi may merely be a concept, but that does not mean he does not affect what is happening.
The question posed here is interesting, and Pan's Labyrinth (2006) ascribing to this tradition of 'magical realism,' does it as well. Forces are at work in both The Devil's Backbone and Pan's Labyrinth that are simultaneously present and non-present. Derrida would say that these forces reject the way we conceive of Western metaphysics. Marx would probably just say that this is how philosophy becomes reality. Either way, the ideas play out in an interesting fashion, and are perhaps even more interesting when considering that the backdrop of both films is the Spanish Civil War.
I refer to the specters of 'del Toro & Almodovar' in the title, because Pedro Almodovar actually produced The Devil's Background, and made the choice to have the narrative occur during the Spanish Civil War, which del Toro (a Mexican director) chose to continue with in Pan's Labyrinth. With the similar thematics of each film, and the sort of collaboration between these directors, it seems as if they are putting certain ideas, certain constructs of language, into circulation. So that while we may doubt the actual reality of the fantasy elements within the diagetic story of these films, we cannot doubt that they have a presentness in terms of their impact on these diagetic stories.