Nature abhors a vacuum, the saying goes. Gases will expand to fill a space, water seeps, life flows and adapts to exploit environmental niches. Creatures in littoral zones fight against the rigours of osmotic pressure with every changing tide. Transitional times and transitional places exert the greatest stresses on any being. The pressure to change from one state to another.

Once there was a place, a place of cliffs and swell and winter's crashing storms, where ravens soared on ruffling updrafts and scrubby, bent trees scrabbled for existence on thin soil where coarse grasses ruled. A wild place, a place where people might go to remind themselves of the power of the Land. A place where children might dare one another to gaze over the edge to water-blackened rocks and malachite surging far below, despite the stern warnings of the mature and fearful. A place where folk might come to send offerings tumbling from Earth, through Air, to Water. A place where, on dark nights, the transitional arena was alight with phosphorescent fire.

Wild, that place, yet secure. A place that had a position, a role, a life. It had unseen yet readily-sensed boundaries, a self contained within.

Then, one winter, Sister Enemy Sea produced a storm the like of which that place had never seen. Winds howled, Sister Enemy clawed and bit and pummelled at the rocks, sucking and pounding and roaring. A deep tremor came from within the earth, up into the rocks and cliffs, shaking them apart, cracking them, ripping them asunder and hurling the pieces into the waiting maw of salt water. The place screamed, its being torn apart, rocks squealing against one another, trees moaning and crying out in pain and fear. Soil bled down cracks and vanished.

Cliffs crumbled and slumped, grass and trees were pulled down into the sea, buried under mud and rubble. Tremor and Storm left a massive scar on the landscape, and a hole in the thoughts of the people. The self of that place clung on, to the scar and the rubble, ghostly and in pain, until there was none who knew what it had been like save the soaring ravens and Sister Enemy Sea.

Sister Enemy Sea had no time for memories, or care. But the ravens remembered.

A farm, old by generations, once the proud manor of a high-ranking family, now home to someone quite different. It sat on a low ridge that stuck out from the side of a hill in a rolling landscape of moor and subsistence agriculture. It gazed out over the south-west, and Autumn sunsets would paint its face in oranges and reds, distant fire reflected in rarely-washed windows.

A strange farm, the buildings in varying states of disrepair, the old barn dusty and littered with rusting machinery, skeletal remains of a more active existence. It had been a different time, perhaps even a different place that had last seen the cow shed occupied by warm and lowing ruminants. A few chickens, almost wild but still fearless, scratched around the disused farmyard. Some of the outhouses and sheds were still used, but those that lived there no longer worked the farm.

The garden, large and semi-wild, was at the front of the house, grass beginning on the far side of the last remaining gravelled section of the drive. It was no longer formal, and was full of secret, hedge-bounded corners. An old apple tree held out strong, straight branches and gave a crop that rarely failed. Foxes visited this garden, and hares, even the occasional badger. The garden itself was a transitional place, but closer to the Land now than People.

On the grass, in a patch of drowsy summer sun filtering through the tree leaves, two children lay facing one another. Butterflies and bees danced and hummed around them, oblivious. They were of indeterminate age, these children, older than five but younger than ten, and of different, yet also strangely indiscriminate sex. One was stockier, more muscular than the other, slightly darker, seemed perhaps more male. But these were children, and therefore sexless.

They lay with faces almost, but not quite, touching and eyes closed. They could have been sleeping were it not for the sense of absorbed concentration. The darker one twitched, moved a little, and one hand touched. Eyes snapped open simultaneously and they moved together, seeming almost to combine into one, single form.

They were twins, conceived from the same beginning, derived from the same source. It made no difference that they did not look the same, they were twins, identical, and no one who knew them questioned that. Strange twins though, more inseparable even than most, forever touching, constantly going off together, no friends but each other and the Land itself. Not that they would have been able to make any friends even if they had felt the need; they were the only children in that disparate and wide-spread rural community. Twins as strange as the place they lived. Twins so close to the Land that they were almost a part of it.

In some senses the farm, the community, the landscape, the hills, the woods, the orchards with their complement of busy hives, the garden, the house itself, were there to contain these twins, melded together by those who remembered to provide context and framework. Even transitional places must have borders and some form of structure.

If you had been able to ask these twins questions, ask them about the world, you would find that this was all they knew. Or perhaps that what else they did know was not something you yourself knew. Or perhaps they would cling together and look up at you with wide, wary eyes and you would find yourself growing increasingly uncomfortable until you were forced to let them be.

They lived together in that old, once proud farmhouse with their Father. They loved one another deeply, the twins and their Father, but there was little obvious affection. He had never tucked his children in at night, had not sat them on his knee since they were old enough to start remembering things consciously. He made no obvious allowances. A special treat meant a blind eye obviously turned to some minor infraction. There were no holidays, but then these twins never went to school.

They were trained, yes, but they did not go to school.

They were trained by their Father, but more by their Grandfather, who lived in a little cottage perhaps a mile from their farm. Not far for children used to trekking across moors and hills, not even those so young. It was also their Grandfather who was the most stern with them. It was their Grandfather who had sat awake all night for four nights one cold winter, on a wooden chair between their beds in their slope-ceilinged attic bedroom, keeping them in their own beds, keeping them apart. He sat awake all night, ignoring stifled sobs and wide eyes, bright with tears that glistened in moonlight, and in the morning went home while their Father served them breakfast in accustomed silence.

Grandfather also had the small, dark room where the hardest lessons were learned, the hardest of all each year on their birthday.

The twins had other people in their lives. An old woman, old past the point of gender, came round every few days to wash clothes, bring odd groceries and do some cleaning. The butcher from the village, who would deliver paper-wrapped parcels of meat on his way home sometimes, leaning his bicycle against the wall by the side door. The Master of the Hunt, who would let them talk to the hounds and the horses to discover what hounds and horses know, and his wife, who would cut their hair when Father had more important things to do. The poacher and the ghillie, who taught them similar things in different ways, for one had taught the other. The farmer who worked their Father's land and kept two heavy horses whose gentleness was matched only by their size, and who would fetch them over in cold springs to help him tend orphaned lambs.

There were relatives too, Aunts and Uncles who would stop by occasionally to see how they were doing in a strangely distant way. There was also the occasional stranger who would come to see their Father and viewed the twins with peculiar confusion, but often left a parting gift, invariably as an afterthought. There was a model Lancaster bomber hanging from the twins' ceiling that they had acquired that way. A man had arrived one day, in a state of deep distress, to speak to their Father. His son had died, been killed, and the plane had been for him. He left it with the twins and left the immediate pain of his son's loss with it, keeping only his memories and spirit.

It was not an easy life. These twins had not tasted chocolate, or known central heating. Summers were hot but winters were cold, with livestock-slaying drifts of snow and frosted shapes on the inside of window glass. On winter nights they would sleep in one bed, shivering together in thick pyjamas under two sets of blankets, limbs entwined, breath making warm, damp caves in the bedclothes.

On the coldest of nights, when Winter's icy fingers stole every scrap of sleep, they would shuffle downstairs, wrapped in their blankets, and beg to be allowed to sleep on the floor by the fire. They asked rarely, not to abuse the privilege, and their Father knew this. On the coldest nights he never refused. They would bed down, two bodies in one entangled pile, and he would make them hot milk with honey or cocoa, the milk simmered so as to form a thick, sticky skin when it cooled slightly. Curled up together, with milky moustaches and warm at last, they would drift off to the soft shushing of their Father's thoughts, so unlike those of most adults, the smell of his brandy and the sweet, milky aroma of each other's breath.

In the hot, close nights of Summer they slept naked in their own beds, but often shared dreams, and sometimes woke up to find one had crawled in sleep across the floor, wrapped untidily in a sheet, to sleep leaning against the other twin's bed, head or hand maintaining contact.

Neither their Father nor their Grandfather had ever really managed to keep them apart. Some of their relatives would comment upon this, frowning, but their Father would only shrug and smile faintly, and occasionally suggest talking to their Grandfather. After those four nights of vigilance proved that they would be so distressed by forced separation that they would begin to crack and withdraw, lying awake all night crying, it was decided to let them be.

Separation would come soon enough, and even the twins knew it, although they neither understood nor discussed it.

On some nights, often in late summer, they would sneak out together in the night and go up onto the moors to be together and marvel at the stars, always on the look out for meteors and secretly hoping for an electrical storm. Sometimes the thought of the separation that was to come would make them hold each other close and still it was never mentioned. They could feel it in each other's thoughts. They could get so close that their minds became one, their bodies a confusion of limbs and skin that could belong to either. They would sneak back, before the first pale fingers of dawn began to obscure the stars, theatrically avoiding creaking stairs and squeaking floorboards.

They grew together, each being moulded according to design and intended role, slowly being changed from two parts of the same whole into two separate and supposedly independent beings. However they never grew apart. Their games of lying so they could feel one another's breath and seeing who would be the first to touch took longer, but the darker one still always lost, even though his sister never wanted to win. The lessons grew harder because their ability to understand why they were being taught became greater. They spent more time comforting one another. They spent more time alone, unsupervised, going in search of badgers and crow's nests and learning about the difference between People and Place. They followed the hunt sometimes, tracking, out-thinking. The girl liked to play with the hounds. She liked to play with the riders, if she was being particularly vicious.

She was always the more precocious one, always the one to jump straight into the river while her brother sat under the willow, fearful of pike. She was the one to jump out of the pollards, to climb higher, to go that little bit further. They both generally had their fair share of cuts and scrapes, but she was the one who had to be carried home more than once with a suspected broken bone, and she was the one who had to be dragged spluttering and crying from the water by the poacher one night because she got too close to the bunyip, despite knowing better. She was the more fey, understanding and being expected to understand certain things instinctively, understanding she would later share with her brother with a gentle touch on his head that moved below skin and bone and mingled thoughts and feelings.

She was the one they would take, eventually. She was the one conditioned for a life of external control, but her brother was the more human, the one who responded best to the training. Two parts of a whole, moulded in limnal space into two separate beings but neither truly complete without the other.

The day came suddenly, but was preceded by omens and portents that left them tearful and clingy without fully knowing why. It was their thirteenth birthday, time for the hardest lesson of all.

They came in the morning, in the afternoon, at dusk, at night, on a day when everything was changing and the world started to die. A cold wind blew and a storm howled, lashing rain in the dusk as the bright sun beat down upon hard baked mud on the farm track. Trees stood still and oppressive while the wind and rain whipped at their branches. A car pulled up, a big one, shiny and new-looking, and with not a speck of dirt upon it. Its colour was indeterminate but cold. The windows were dark enough to be opaque. It had alloy wheels. It stopped on the farm track, just outside the line the twins considered to be the perimeter of the farm itself. Their Father, looking suddenly like their Grandfather, tall and straight but bent, tired and sore inside, took the twins out through the side door to meet the end. They were deeply afraid.

Two men, the biggest men the twins had ever seen, burly in the way of bouncers or wrestlers and dressed in smart, expensive suits, stood just within the perimeter and called the girl over, not speaking a word. The twins' Father stood with one hand on her brother's shoulder, not just holding him fast but leaning on him for support. The girl took some faltering steps towards the men who had come for her, face a mask of hurt, determined not to cry, to be strong for her brother. She resisted the coerced urging to go to them but could not entirely deny it.

They came to get her when she slowed to a near halt, and took her arms, gently but firmly. She looked back towards her brother in agony as they led her away, seeing his lost, betrayed, hurt expression and blinking back hot tears of anger and resentment and fear. The link between them seemed to stretch and writhe, a piece of elastic at near breaking point, their hearts bursting with a tremendous pain as if the link was ripping their core from within them.

With small, involuntary cries, they broke free simultaneously and ran towards each other, skidding to a halt on their knees halfway between two states, stones gouging cuts that seemed inconsequential and even necessary in their knees. They clung to one another, faces pressed against one another, tears sandwiched between skin. Soul-wrenching sobs shook their combined form, and they whispered unintelligibly to one another, shared thoughts making harsh promises that they would find one another again. No matter how long it took, no matter what or who stood in their way, they wouldn't forget, would always search, that they would find one another eventually. No matter what, they would find each other.

Then the men took her. Forcibly this time, lifting her by the arms and bundling her into the car, leaving one twin inconsolable on the dying Earth.

And despite their promises, they did forget. They forgot because the world and their Family made them forget. They forgot because their world died and they began again in a new world, as new people, a world where neither had a twin. But some part of them always remembered, as ravens always remember.

More than a quarter of a century later, two strangers meet eyes across a rickety wooden gate. Nature abhors a vacuum, and transitional times cause great stress. Sometimes the only thing to fill a space is the thing that was removed from that space in the first place. Sometimes nothing else that tries to fill that particular hole can succeed. Just occasionally the thing that was removed from a place finds that place again, and rediscovers what it means to be home.