In 2016, a man from North Carolina travelled to Washington, DC to fire a gun through the doors of a pizzeria called Comet Ping Pong. He had been reading viral reports that 35,000 “malnourished, caged and tortured” children were rescued from a tunnel network underneath major US cities, through which they were transported and delivered to Democrat politicians. The conspiracy theory had a precursor in the form of the McMartin preschool case during the 1980s, when the owners of a Californian day school were accused of ritual child sexual abuse. This conspiracy also involved reports of tunnels through which children were spirited; some of the most fevered said that children had been flushed down the preschool’s toilets to be deposited in underground chambers below.

Tunnels function as architectural doubles to established information systems, and consequently, appear often in the conspiracy theories that erupt into the mainstream. This is also partly because the real-life tunnels that exist underfoot are deliberately secretive. In the US, D.U.M.B.s, or Deep Underground Military Bases, feature prominently in conspiracy theories (the acronym, if you’re conspiracy-minded, an irresistible provocation). And American subterranean architecture is truly astonishing: the Cheyenne Mountain complex built under a mountain in Colorado features 15 three-story buildings that are protected from earthquakes or attack by a system of giant springs that the buildings sit on. (Curiosity about these engineering mysteries might also incorporate a desire to participate in such a sophisticated governmental construction project, while above-ground cities are left to fall to pieces.)

Under London’s streets run not only sewer systems and drainage channels but also sheaths for electrical wires, military citadels, a tramway, gas supply and wartime bunkers. There is what a character in an Alan Hollinghurst’s novel The Sparsholt Affair (2017) calls the “proletarian labyrinth” of the Tube; there are the rivers that were lost when streets and houses were built over them. A new “supersewer” is due to be completed this year along the Thames: a tunnel between 7.2m and 9m wide and 22 miles long that will run underneath the riverbed between Hammersmith in the west and Beckton in the east. It will cost nearly £5 billion. Though sewage systems are essential for the functioning of a city the size of London, they also represent an engineering and artistic achievement. After the Great Stink of 1858, when the Houses of Parliament were overwhelmed by the smell of the sun-heated Thames, Joseph Bazalgette built the sewer system which has served the city well up to the present, which utilises bricklaying techniques of such sophistication that the ability to recreate them has been lost.

Tunnels are phenomena of both culture and function, and have long been sacred places. Four and half thousand years ago, people made a long trek across the mountains and deep inside a cave in Sulawesi to paint two warty pigs on the wall; 120,000 years ago, humans in what is now Israel started burying their dead in geologic features like Qafzeh Cave. Ancient Iranians worshipped Mithra, one of the Graeco-Roman deities central to Zoroastrianism and the god of light, in underground caves dug into the earth – not simply travelling a few metres into the rockface, but walking for hours down through narrow shafts underground, sometimes forced to crawl through passages. Mithra’s followers stayed underground for long stretches, taking part in a seven-stage ceremony. According to St Jerome, the follower would travel from being a Corax, the crow, to Nymphus, the occult, Miles the soldier, Leo the lion, Perses the Persian, Heliodromus, the Courier of the Sun, and finally Pater, the Father, who represents Mithra himself. Over the course of the ceremony the initiate would be baptised in underground pools or rivers and have honey poured over his hands; finally, he would ascend back to the light above, which must have been shattering: leaving one’s self behind and entering into the astounding glare of Mithra’s light.

In some of the deepest tunnels to contain cave art, the lines depicting the animals are layered, and some have suggested that by candlelight, the animals would flicker as if moving – making cave art a very early version of the cinema, or at least a form of immersive theatre. Similarly, the Mithratic ceremonies within the caves would have been visually and aurally intense, with the running water in the darkness, the bare, thin light of the candles, the heat and probably the smell – of damp rock, melting wax, and other people. Flickering is often linked to the functioning of the unconscious, produced from the “obvious association between the cinematic experience with dreams and voyeurism,” as Central Saint Martins lecturer Paul Rennie notes: “The darkness of the cinema and the flickering experience of the film also correspond to our notions of memory and dreaming – both important aspects of the psycho-analytical interpretation of the unconscious.” As for film studies today, so as for the Mithraic initiates, who would proceed along the long, narrow tunnels in order to access truths unavailable in the sharp light of day. Though the academic consensus is that the Mithaeic tradition became Christianised, some believe that it was pushed underground and continues as a form of Satanism, hidden away, running parallel.

To go down the tunnel is to enter the self. All over the world, people who have nearly died have reported back an experience of travelling down a dark tunnel towards a widening light. One of the most popular theories for the prevalence of this impression is that in the moment of death, one relives the first trauma, namely that of being born. This is refuted by Susan J Blackmore and Tom S Troscianko, authors of “The Physiology of the Tunnel”, who make a number of compelling arguments:

“It is implausible to suppose that the infant would perceive the world in a form that could later be recalled by an adult with totally different perceptual capacities. Also the birth canal is nothing like a tunnel with a light at the end, and in any case the fetus is pushed along it with the top of its head usually emerging first, not its eyes.”

Instead, the body might produce the tunnel itself. As they explain, when the brain is starved of oxygen, inhibition is suppressed, which causes cells in the visual cortex to fire randomly and “noisily”. Using retinocortical mapping, scientists observe that these cells are centred in the eye, and sparser to the edges. “The effect will appear like a flickering speckled world that gets brighter and brighter towards the centre,” they write. “Is this the tunnel?”

Tunnels are a corporeal metaphor: the human body consists of several tubes and tunnels (or one big one with tributaries, depending on how you see it) and tunnels have a particular intestinal potency. Shakespeare used the phrase “the bowels” in several of his plays. In King Henry IV, Part I, Hotspur refers to “the bowels of the harmless earth”. In Richard III he used “the bowels of the land”. In Coriolanus, Aufidius promises his friend that they would “muster all / From twelve to seventy, and pouring war / Into the bowels of ungrateful Rome, / Like a bold flood o’er-bear”: an image of an enema, perhaps inspired by Shakespeare’s reading about the real-life Tunnels of Claudius, which the Emperor constructed to partially drain the Fucine Lake in Abruzzo (at the opening ceremony, at which Claudius organised a mock sea-battle then opened the sluice-gates, the water flooded in and backed up, forcing the Emperor to flee up the banks).

The vaginal tunnel is less often evoked in literature, and it’s more shocking when it is. In John Milton’s Paradise Lost, Satan travels across Hell to the gates that bar entry to Eden, and finds Sin there:

“a formidable shape;
The one seem’d Woman to the waste, and fair,
But ended foul in many a scaly fould
Voluminous and vast, a Serpent arm’d
With mortal sting: about her middle round
A cry of Hell Hounds never ceasing bark’d
With wide Cerberian mouths full loud, and rung
A hideous Peal: yet, when they list, would creep,
If aught disturb’d thir noyse, into her woomb,
And kennel there, yet there still bark’d and howl’d
Within unseen.”

Sin’s vast snakelike body contains a yawning vagina in which the hell-hounds creep, a deeper place inside the already subterranean Hell. It’s not surprising that in Milton’s Christian imaginary Sin is characterised by excessive and grotesque femininity, though in theological terms, Milton is also emphasising the proximity of the vaginal canal to sinfulness – the vagina is where one acquires original sin, in the passage from womb to world.

Returning to the site of original sin, or rather the state of infanthood, is the central tenet of Donald Winnicott’s much-cited theory of breakdown, that “fear of breakdown is the fear of a breakdown that has already been experienced”. He rejects the term “anxiety” in favour of “primitive agony” to describe that which is feared, one of which being “a return to an unintegrated state”. Sin’s impossible body is a version of this, an unformed and malleable mass around the central womb, the prospect of reintegration with the mother.

This reintegration threatens – and appeals – when calamity strikes. In a 1952 interview, Carl Jung said, “I was terribly shocked when, still a child, I read the Book of Job for the first time.” That story tells how Satan comes to God and points out Job, a pious man living in Uz, who is blessed with wealth, three daughters, seven sons and a loving wife. He also has seven thousand sheep, and three thousand camels, and five hundred yoke of oxen, five hundred she-asses, and a very great household. Satan suggests that Job is only pious because of his earthly riches: God, to refute Satan’s insinuation, sends a fire to burn up the sheep and camels, and causes the house to fall down on Job’s children. After Job still doesn’t curse God, God “smote Job with sore boils from the sole of his foot unto his crown”. Then Job, sitting in the ashes of his house, speaks:

“Let the day perish wherein I was born, and the night  in which it was said, There is a man child conceived.Let that day be darkness; let not God regard it from above, neither let the light shine upon it.Let darkness and the shadow of death stain it; let a cloud dwell upon it; let the blackness of the day terrify it.As for that night, let darkness seize upon it; let it not be joined unto the days of the year, let it not come into the number of the months.Lo, let that night be solitary, let no joyful voice come therein.Let them curse it that curse the day, who are ready to raise up their mourning.Let the stars of the twilight thereof be dark; let it look for light, but have none; neither let it see the dawning of the day:Because it shut not up the doors of my mother’s womb, nor hid sorrow from mine eyes.Why died I not from the womb? why did I not give up the ghost when I came out of the belly?Why did the knees prevent me? or why the breasts that I should suck?”

He wishes to return to the night when he was born, when the announcement of his birth was made, and for the day itself to be swallowed up into nothingness: he wishes to return to the womb, forever. He laments, “For the thing which I greatly feared is come upon me, and that which I was afraid of is come unto me. I was not in safety, neither had I rest, neither was I quiet; yet trouble came.” Job, in the literal ashes of his life, disintegrates; becomes foetal. “In other words,” Winnicott writes, “we are examining a reversal of the individual’s maturational process.”

Jung understood this, in the context of Job, as a problem of ethics. In his 1952 book Answer to Job, Carl Jung turns the Book of Job into an inversion of what Christians typically consider to be the story’s fundamental theological drama, that of mankind’s badness being contained, directed and redeemed by divine power. In Jung’s telling, God’s fundamentally excessive punishment of Job is demonstrative of God’s capacity for evil, and therefore His incarnation as Jesus and subsequent death is a repair not of mankind’s sinning, but of God’s. Jung describes here a dreadful displacement, in which Yahweh – light – becomes dark; as he says: “I discovered that Yahweh is unjust, that he is even an evil-doer.” This reveal threads through his work. Reversals, replacements, projections and transferences would inform much of his psychoanalytic theory, including his invocation of the shadow as a part of the unconscious – which, if rejected, can take on autonomous qualities and inform the behaviour of the apparently conscious self.

When I was a child, I was terribly disturbed by one of the stories in a huge, purple-covered book of Hans Christian Andersen’s fairy tales, “The Shadow”. In a vaguely Eastern setting, the story tells how a learned man one day on his balcony invites his shadow to go through the door of the adjoining balcony. The shadow does, and then disappears, returning years later having grown into the appearance of a man. Firstly friends, the learned man and his shadow gradually swap places; the shadow begins referring to the man using the informal address, and the learned man is forced to pretend he is a shadow so that the shadow can marry a princess; when he threatens to reveal the lie, the shadow has him executed.

Children are often deeply frightened at the risk of authority – so powerful in the child’s day-to-day life – being overturned. This is stronger than a fear of chaos, but a terror of essential undoing. As Job says to God:

“Remember, I beseech thee, that thou hast made me as the clay; and wilt thou bring me into dust again?Hast thou not poured me out as milk, and curdled me like cheese?”

This is the same primitive agony that underlies the shadow story: that what you make has the power to ruin you. Before he speaks the above lines, begging God to remember him, Job says: “Thine hands have made me and fashioned me together round about; yet thou dost destroy me.”

In The Hunters or the Hunted?: An Introduction to African Cave Taphonom (1981), anthropologist Charles Kimberlin “Bob” Brain proposed that the prey status of early homo sapiens is what triggered human social survival and life as we know it today. Dinofelis, he proposed, was a large cat with huge teeth and a powerful jaw, able to eat “all parts of a primate skeleton except the skull”. This cat hunted humans at night, probably silently. People fleeing were driven into caves, where they could make and keep alight a fire, and where human social ties began to form at the rim of the light.

In Nicholas Shakespeare’s biography of Bruce Chatwin, Shakespeare describes how Chatwin travelled to Pretoria to discuss Dinofelis with Brain, taken by the idea that human sociality was formed not from aggression – as in the hunter hypothesis – but from fear. His hypothesis (which Brain was dubious about) was that once the cat is lost – turned from predator to prey, once people could hunt in groups – people are forced to invent and reinvent the monster. This triumph over the initial aggressor represents nothing more than a Pyrrhic victory: “Has not the whole of history been a search for false monsters… a nostalgia for the beast we have lost?” We invent monsters, whether in one another or in stories, in order to keep the engine of our fear alive. Fantasy, then, is inextricable from terror, and the fear of the other is primarily created by the self; is, even, a fear of the self.

Thus, the tunnel: the place where we negotiate between two moments, birth and death, the very prevaricating space of existence. The conspiracy theorists fixate on the child as the figure who needs protecting from the terrible knowledge that the tunnel holds, in so many of its iterations: of dissolving the self. In Blackmore and Troscianko’s article, they consider this as a scientific possibility. “These mental models are not something we construct,” they observe. “Rather ‘we’ are the mental models constructed by the brain.” The sense of self is a model and so the sense of the other is a model: in the near-death experience, the models collapse, and the “dissolution of the self model” becomes dominant. “The physiologically induced tunnel can be one way of realising something important about ourselves, something that can change our lives: that is, that we are mental models and nothing more.” Death loses its sting; or, self-knowledge is always a form of annihilation. The tunnel represents an inner knowledge that contains the destruction of worlds. This is what the man with a rifle was seeking, however unconsciously, behind the doors of Comet Ping Pong. .