If there’s a scientific theme in Falling, it’s about the way the human brain really works and its interaction with the environment.

I set out to write a horror story with some scientific trappings, but it gradually (over the course of decades, in fact) morphed into a Grand Unified Theory of everything I know and like about ghosts, monsters, the paranormal, brain science and their intersections in biology and physics.

I wanted to write a ghost story that came as close as possible to explaining why ghosts exist.

By virtue of the demands of dramatic tension, most horror stories contain monsters or antagonists who don’t seem to know they’re scary and usually don’t even intend to be. When the mystery is solved it turns out they’re just trying to communicate something or kill someone (no differently than a lion hunts and kills a gazelle on the plains of Africa – an act of nature that can’t be termed ‘evil’ no matter how brutal or frightening).

Even paranormal entities that are termed ‘evil’ are about much more than just frightening us. Sure, they want to consume our souls or something similarly nasty, but they’re actually following strict rules and constraints about their own existence no different than a lion hunting a gazelle.

To me, that rendered a lot of what happens in horror movies that feature paranormal entities kind of redundant. Of course it’s scary for us in the audience, but why would the ghost or monster choose that moment to burst out of the closet, appear behind the teenage heroine in a mirror or thrust a bloodied, grasping fist up out of a grave?

Falling was a way to figure out why all those things happened, and the more I (re)wrote it, the more important it became to me to use the story to investigate it.

In the first drafts and versions I did the same thing horror novels and films have done since time immemorial – I wrote scenes of scary stuff for their own sake, often with no real rationale about why specific things happened.

But after the central thesis gradually came together, the first task was to sketch out a timeline about how the supernatural entity at the heart of Falling grows and changes, how it seems to ‘discover’ new powers and wield them.

Next was to go through the whole book and mark down every instance of the paranormal – from power lines emitting sparks to the appearance of some hideous creature – and come up with a plausible reason for it to be there.

Every cultural artefact from the horror genre, be it a book, movie or anything else has a common thread, you see. Because of the nature of drama, the danger or threat has to start small and build to an inevitable climax.

It was no different in Falling – the first manifestation of the paranormal (although nobody has any idea at the time) is when Dale crosses the bridge by train early in the story and feels pain in his back for the first time in years, and its final manifestation is when it manipulates spacetime itself and sends he and Tim back to the past.

Why, the requirements of narrative plausibility demanded, did it build like it did, and why did certain phenomena/apparitions/manipulations of matter occur when they did?

Sometimes I had a cool monster I knew I wanted to keep, like the creature that attacks Dale and Tim in the Sydney Skyway cable car ride. And sometimes the timeline I constructed called for a new ghost or phenomenon.

A big part of it was making specific phenomena personal to each character. Dale has more than one interaction with what I eventually christened The Ghoul (the man with half his leg cut off trying to crawl his way out of the white Mitsubishi), which made it kind of easy – it just meant giving The Ghoul a starring appearance in the collapse sequence.

During young Dale’s flight to escape the bedlam raining down around him as the bridge collapses, he passes the dead gaze of the man who became the poor victim, a memory that unconsciously stays with him and becomes a common feature of his relationship with what’s going on.

For Donald, the metallurgist, it’s a cheesy werewolf costume from a movie he saw on TV as a kid. For Vicki it’s the oppressive panic that builds in her whenever she consciously thinks about the bridge, a panic only sexual release can tamp down.

And, happily, the cable car creature was able to stay thanks to a gargoyle on top of a headstone near Tim’s mother’s grave in Queensland, one that had never even given him so much as a sleepless night but which was there in his brainwaves somewhere.

Waves and particles

Which leads me to the other major aspect of what I wanted to achieve with Falling. To say ‘it’s a demon from another dimension’ means nothing to a physicist or a biologist. It must be – as everything in nature is – the manifestation of forces on the environment that human senses (and machinery) can perceive. But why these manifestations of energy? Why do they behave in this way? What – to apply inappropriately human motivations on natural forces – do they want?

Here’s the thing about nature. Drill down as deep as we can measure or hypothesise with all the scientific enquiry we can apply and it’s all just waves and particles moving in a medium according to four fundamental forces – the weak and strong nuclear forces, gravity and electromagnetism.

Everything – everything – is an electromagnetic field. You are, I am, trains and cars are, TV and satellite signals are. All matter and motion takes place on the substrate of an electromagnetic field.

All discussion of disembodied soul and personality and our most cherished beliefs about what makes us who we are aside, everything that goes on in our brains is part of that vast electromagnetic field known as The Universe.

Every thought, dream, fear, idea, your subconscious, your memories and experience, the constant narrative stream of your life is a series of electrical sparks in your brain as neurons connect and disconnect across synapses using tiny electrical signals.

It’s an awful thought to many, but your entire life and everything you’ll ever know, forget, want and love can be boiled down to a constant miniature lightning storm going on in a kilogram-and-a-half sac of pulpy flesh in your head.

Know what else is comprised entirely of electromagnetic impulses in a given field? Everything in the universe we can’t account for – including ghosts, spirits and the supernatural.

If they manifest as apparitions moving through walls, that’s visible light, which is an emission of energy along the electromagnetic spectrum. If they turn lights on or off, that’s an effect on electrical currents, which is child’s play for electromagnetic impulses.

If they appear to you as your long dead grandmother telling you to go and look in the locked chest in the attic for the real copy of her will, that’s not only a visual manifestation of electromagnetism, it’s something particular to you. Where do the memories and knowledge of your long dead grandmother live? In your head, among the tiny electrical sparks in your brain.

From there it wasn’t too big a leap to imagine that the electromagnetism of a haunting or ghostly presence can interact across the electromagnetic medium with the electrical impulses in our brains, make us see ghosts and monsters and more importantly, make us see ghosts and monsters that mean something to us.

A battery for fear

Why would they do that? Simple – does some stupid movie monster you saw as a kid still frighten you if you’re in the right frame of mind, like the dumb werewolf costume from a movie as remembered by Donald, the university metallurgist?

Even if we’re not frightened anymore as such, we can still remember how much it used to scare us. We remember how aspects of it (the monster’s shaggy pelt, its Cro-Magnon lope as it chases a screaming victim through the dark streets, the sound of its angry growl) are ingrained in our memories of it, the specifics outsized after remembering it as many times as we have and far more frightening than the visuals that scared us so badly to begin with.

The secret I made up is found in the amygdala, one of the brain regions they say synthesises the fight or flight response. We’ve all seen those textbook cross sections of brains with dotted lines, section A devoted to sensory information, section B to emotion, etc. Even with our current understanding of neurology and cognition those diagrams are woefully inadequate – no brain region is as functionally cut and dried as we think, and they’re certainly not so segmented as those high school biology textbook diagrams has led you to believe.

So I’m the first to admit it’s not nearly as simple as saying the amygdala is the ‘fear’ centre of the brain, but it’s certainly a handy and very large cheat I recruited to make sense in the story.

A cloud of dread

Something else most of us don’t realise about the brain is how perfectly insulated it is. If a thunderstorm prompts a wave of static over an old transistor radio or that rhythmic, repetitive two-beat buzzing sound rings out from PC speakers when there’s an old mobile phone nearby, why doesn’t electromagnetism interfere with the electrical signals in your brain?

If you stand too close to a magnet revolving around a coil in a power plant, why don’t you suddenly think of a green car when you try to conjure up an image of your mother?

We have technology that does an okay job of watching brain activity like fMRI and EEG machines, but individual electric sparks across synapses are far too small to detect – there are billions of them every split second that are too low powered and take place in too small an area.

There’s not much that can impact those electrical signals except in very overarching and crude ways. One is the historical practice of electroconvulsive therapy (which is like using a wrecking ball to tap a thumbtack into a corkboard), but a recent technique with a bit more finesse is called ‘transcranial magnetic stimulation’ – look that up and prepare to be horrified at the implication for your immutable sense of self.

So I needed to come up with a way of the electromagnetism out in the world interacting with and even changing the electromagnetic fields in our brains – which manifests as quite literal changes in our conscious experience.

The theory, you see, is that there was a huge and very strong field surrounding the nearby electromagnetic medium (buildings, cars, even the very air – which is after all part of the electromagnetic substrate because it’s made of the same protons and electrons as everything else) after the collapse of the first bridge.

It came from brains. As so many people died or watched on in terror as others died, it prompted a giant spike in bioelectrical activity in countless brains as they all responded to such fear and threat, amygdalae across square miles of space firing furiously and collectively pumping out huge amounts of energy that would remain there, locked into the very fabric of spacetime.

That’s one part of the theory I can’t take credit for. As long ago as 1925, British physicist and spiritualist Oliver Lodge wrote in his book Man and the Universe that;

‘Occasionally, a person appears to be able to respond to stimuli embedded … among psycho-physical surroundings in a manner at present ill-understood and almost incredible;- as if strong emotions could be unconsciously recorded in matter, so that the deposit shall thereafter affect a sufficiently sensitive organism and cause similar emotions to reproduce themselves in his sub-consciousness, in a matter analogous to the customary conscious interpretation of photograph or phonographic records.

‘Take, for example, a haunted house … wherein some one room is the scene of a ghostly representation of some long past tragedy. On a psychometric hypothesis the original tragedy has been literally photographed on its material surroundings, nay, even on the ether itself, by reason of the intensity of the emotion of those who enacted it and thenceforth in certain persons an hallucinatory effect is experienced corresponding to such an impression.’

Hack away at the archaic language and Lodge is suggesting that past events experienced under emotional duress are somehow ‘recorded’ upon the surrounding matter where they happened. Scientists had come up with the bare bones of electromagnetic theory as far back as the 1870s, but with Lodge’s use of the outdated term ‘ether’ it seems they didn’t understand the full extent of its presence in nature even 50 years later.

As a scientific theory – and however flawed – it rests upon some pretty exciting bedrock. Extrapolate out from Lodge’s idea and in Falling the site of the old Sydney Harbour Bridge is just such a haunted room. The long-past tragedy is the death of hundreds of people and the terror of the millions who watched, and the ether is the electromagnetosphere – a field which comprises the surrounding city, the water, the air – even us.

Of course, the residents of Sydney for decades afterward went about their daily lives with perfectly insulated synaptic activity, so they would have had no idea of the electromagnetic thunderstorm raging over their heads and beneath their feet, manifestations of all that energy waiting to turn from potential to kinetic (active).

And it would have stayed that way forever had a device not come along that bridged the gap.

The missing link

In Falling, that device is the special machine implanted in Dale’s back that holds his spine together and gives him the power to stand and walk again.

I took great pains in Falling to not characterise the entity causing all the mischief as some evil demon or restless spirit intent on revenge. As Tim lectures his friends more than once (including me, I have to be honest), it doesn’t have human intent.

It’s a field of energy that wants to follow its potentiality, no differently than a ball wants to fall to the floor through the potentiality of gravity or electrons want to move around a circuit through the potentiality of a closed circuit (which happens when we flick a light switch.

It doesn’t want to kill or maim or terrorise, it just figures out – not that it has human-like desires to figure stuff out – it can do so to achieve the aim of reaching its potentiality.

Remember, it’s an electromagnetic field. It doesn’t have a concept of emotion at all, let alone fear. All it knows is that it finds a switch it can close to complete a circuit, so it sends power to that switch in an attempt to do so. It feeds more power into the system.

The system is the electromagnetic field in and created by all of our living brains, and it can give the system the jolt it needs to try and close the switch by prompting the reaction that delivers the greatest activity in the amygdala – fear.

It does that by looking for reagents across the medium. In this case they’re electrical sparks that make up our memories of that creaky monster costume, the uncle that used to wear a horrible clown mask and chase us around the house, the time we were lost at the mall.

The brace in Dale’s back becomes the intended switch of the circuit and the epicentre of all that activity. Compared to the electricity in the brain it’s a very imperfect, clunky and badly insulated system, so it was an easy target (again, ascribing inappropriately human intent).

It soaks up electromagnetism from the environment very easily – the reason why the first manifestation of the paranormal is no scarier than pain in Dale’s back as the brace heats up. The power surging through it directly connects the outside world with the ‘fear processor’ of Dale’s brain (the amygdala) because it taps directly into his brain to deliver the electrical signals the on-board computer deciphers from his muscles.

We all know what static electricity does when it tries to overcome the surrounding air resistance. Reach for a metal door handle after walking on synthetic carpet and an electrical spark will bridge the last few millimetres with a loud snap. On a grander scale, positive and negative electrons between clouds and the ground will send a surge of static towards each other to connect in the form of a lightning bolt.

The entity simply sends more power to the brace, and in doing so tries to ‘tune in’ the signal to close the switch, again like the static from an old radio as you get closer to the station’s position on the dial.

It ‘learns’ (enough already with the human-like objectives!), to tap into the entire electromagnetic substrate created and maintained by the world around us, including our own brains. For want of better terminology, it can read your thoughts and figure out what scares you, so it tries to send more power to your own amygdala by showing you all the creepy crawly creatures and monsters under your bed – whatever prompts the strongest reaction of fear in you.

When the characters are afraid in response to those stimuli, the power to the system (the electromagnetic field) goes up, and it gets closer to completing the circuit.

The barrier within

But just like the resistance air exerts between the storm clouds and the ground, the entity trying to close the circuit can’t quite manage it because the well-insulated biomass of Dale’s brain and body themselves are the stumbling block. The more power is sent to the brace through his brain, the higher the resistance grows, keeping it from closing the circuit.

Of course, as Tim realises from his equations, that doesn’t mean a point won’t come when the field is given so much power it overcomes the resistance, just like the static buildup of a lightning bolt-to-be grows high enough to overcome the air resistance.

The same thing happens when we flick a switch and close a circuit in the wiring of our walls – the light comes on because electrons are moving around the system, including through the filaments of the bulb, causing it to glow.

But what’ll happen when the circuit is closed after the switch of Dale’s brace is tripped? The mathematics and physics of the situation don’t say, but one thing’s for sure, it can’t be good.

It starts out by causing electrical heating of the brace, and by the time the story ends it’s deployed all kinds of hideous visual illusions, manipulated matter and even rebuilt matter according to its own aims (which is why it’s a big deal when Tim discovers that the southern pylon structure has turned into the giant monster that attacks Vicki).

Unlike a monster from a horror movie that acts as a screenwriter intends for the purposes of simply doing scary things, the entity in Falling develops over time – learning new skills to bring about its aim (that’s the last time I’ll describe it in human terms, honest).

When the train carriage turns up floating in the harbour having exhumed its grisly cargo, it’s another terrifying reveal because when Albert reports to Tim that the original carriage has actually been recovered and accounted for, Tim realises that it might be conjuring matter out of nothing at all.

It’s final and most shocking act is of course time travel. Tim surmises when they recover from the shock of what’s happened to himself and Dale that they’ve been bought back to the site of the original collapse because it’s the point in spacetime where the field was strongest, the fear of a million amygdalae contributing to a churning maelstrom of active electromagnetic energy that would never be replicated to the same degree.

When the effects thus far have included giant electrical explosions, creatures that attack the living, forces that seem intent on killing, even an electromagnetic pulse that knocks out communication and affects the magnetic field of the Earth itself, it seems like the phenomena associated with the haunting will only get more destructive.

Though it seems ridiculous to a group of professionals in Sydney in the 21st century who aren’t in the middle of a Marvel superhero mash-up or a CGI-assisted alien invasion blockbuster, they might be dealing with death and destruction on an unimaginable scale…