Perhaps you store your grandmother's bones – assuming she no longer needs them - in a box, buried deep in the ground for safekeeping, but not so deep that they can’t be dug up again, if wanted or needed, though under what circumstances I can't begin to imagine. (Begin to imagine). Or you keep them in an urn, the bones mostly reduced to ash by purifying fire, except for the hardest, most resilient bits, that might still be recognizable as bone fragments, if you were to take the time to rake through the grey dust to look for them, though under what circumstances I can't begin to imagine. (Begin to imagine).

I have my grandmother's bones, or so I’m told. Instead of buried boxes or burnished urns I keep her bones much closer. I inherited them before birth, in all their chalky brittleness, placed into my body inside my mother’s body, slowly growing with me over the years, though not so slowly at first. No, at first they grew quite quickly, and despite their slenderness, or because of it, they were supple, almost pliable, like green wood, like saplings. I survived falls and tumbles and no small amount of beating, some of it allegedly corrective, much of it coercive, recreational on the part of my teen peers. I survived. Not unscathed, but intact, not a single one of my grandmother's bones broken by those diligent and careless sticks and stones and words. No fractures, cracks, or breaks. Or none that any x-ray could detect.

But now, now, they no longer have that same youthful density, that useful pliability. I walk carefully. I no longer run. Hiking has become fraught and circumspect. I worry my grandmother's bones might shatter at the slightest fall. On mountain trails I carry matching spring-laden metal poles to more evenly distribute the risk, fragile as eggs in four-legged baskets.

My inherited bones survived a car crash. I crawled from the wreckage, after a brief post-crash interlude of inverted dangling, still strapped in, saved by my safety belt. And my grandmother’s bones? Well you already know. Beneath the bleeding and the bruising, miraculously unscathed, their integrity preserved. Much as I would like to take credit for their preservation, my grandmother's bones were saved by a strap of tightly woven synthetic cloth. The belt held. Where metal had buckled, the belt held. Where glass had shattered, the belt held. Where fibreglass had split and cracked. The. Belt. Held. For this I am grateful. I owe my life to a car manufacturer, to the legislators who insisted on the presence of safety belts in these killing machines, to the road safety campaigns that indoctrinated me into developing a lifelong habit of inserting a buckle into a notch, to the automatism of snapping in the clasp with a satisfying and reassuring click, to the workers who laboured and manufactured and installed all these things. Loathed as I am to admit it, I can count the continued safety of my grandmother's bones as a victory for the interconnectivity of capitalism, of greedy globalism, of the entire messy intertwined process of pulling things out of the earth and recombining them into other things, like wheeled machines that wend and wind their way over the surface of the planet, wheeled machines that cost millions of lives worldwide every year, that cause countless life-changing injuries, one wheeled machine that in this instance rattled over poorly graded gravel roads through vast empty treeless Namibian plains towards sunset, machine dragging a cloud of dust in its wake, a machine that, but for a narrow breadth of cloth, promised near certain death for me, but that in this particular instance did the opposite, saving Granny’s slender bones. Safety belts may - I have no reliable statistic to hand - save more lives than these machines kill every year, though whether this hypothetical, even if it should happen to be true, is all that reassuring, is a moot point. So yes, crawling bleeding, bleeding crawling, from a car crash, through the beatings and the tumbles, crawling bleeding, through the impacts of fists and feet and rocks and sticks, bleeding crawling, through the whole messy business of living life, my grandmother's bones improbably endure.

Now the clear gel is smeared over my ankles, my heels. Now the machine peers under my skin, through my skin. Now the printer sicks out a graph, then another, one for the left, one for the right. Now the doctor’s pencil is pointing at the place on the graph where my grandmother's bones are to be placed. Traffic light colours. Do they sit in the green zone? They do not. The amber zone? Nope. They are in the Red Zone. I am in the Red Zone. Not deep into the zone, not yet, but well over the border from Amberland. If this were a map I would have already gone past passport control and customs, seen Amberland recede in the rear view. I would have had a moment to adjust to the new signage, the foreign language, the shape and approximate or guessed sounds of its words and place names. Doubtlessly I would already have passed a few billboards advertising products that may or may not already be familiar to me, that may or may not present familiar products in familiar or unfamiliar ways.

I am unexpectedly exiled, along with, and on account of, my grandmother's bones. It takes me a moment to adjust as the doctor’s pencil taps the charts, one for the left, one for the right. This new country, this Red Zone, is to be my home from now on. We take calcium supplements in this new place. I am told that this is essential, despite or because of a childhood of milk, despite or because of an adulthood regularly punctuated with the tang of plain natural yogurt, sometimes sweetened with a little honey when I can afford it. I am told I should seek impact. I’ve had enough impact in my life, thank you very much. I’m not looking for more of it at this late stage. Nothing too hard, reassures the doctor, but my grandmother's bones need some regular resistance. I swim, I offer. Water, whatever resistance it might offer, is too giving, too forgiving. Impact, impact is required, something more than breaking surface tension. The doctor suggests I walk. This I can do, so I walk. I walk in the Red Zone. I start in a small town, hardly more than a village, then keep walking. I walk hundreds of kilometres, muling a backpack, carrying my grandmother’s brittle bones over mountain ranges, across scrubland, through forests and farmland, through towns and villages and cities, through vineyards, seas of poppies, fields of beans, through nasal-clearing eucalyptus groves, past huge methane-belching cows the size of family cars, on and on I walk and walk and walk until I taste salt in the air, until I reach a distant coast, then I walk along the coast. The doctor says jump, but not too high. I reluctantly jump. I feel I have passed the jumping age, by quite some margin. No longer the gambolling bleating lamb, the little boy mocked and jeered for skipping, joyfully, some would say effeminately, down the lane. It's not the sting of the remembered indignity, how my bookishness made me a target for blows, or not only the indignity. I just, I confess, have a general lack of enthusiasm for jumping. That will be the anaemia, says the doctor, and writes me a prescription for the iron supplements that change my life in ways I never could have anticipated. Goodbye to the indolent lethargy I had long assumed was just my natural state. Goodbye to the fainting fits. Hello pep, and vim, and vigour. I wish my bones could fix that ferrousness, transform that iron to rebar reinforcing. We are all shrouded skeletons in varying stages of growth or decay. Build me an internal iron lattice of struts and beams and buttresses, engineered by Eiffel, by Brunel, a structure whose span is a longer more resilient, if somewhat rusting, life. The doctor pencil-tapping the chart, the graph, the map, brings me back. She says that in this Red Zone lies another invisible border. I will cross it gradually, she cautions, as I move further from Amberland. Amberland where I must have spent quite some time, perhaps years, maybe even decades, without even knowing it. Amberland, the sunlit plains of fading youth I didn't know enough of to make the most of. But too late. I am in the Red Zone now. How soon I cross this secondary invisible border will depend on many factors. Impact. Calcium. Genetics. Safety belts. I take the sheets of paper with their traffic-light-coloured graphs, fold them, slip them into a pocket, my new laissez-passer, tricoloured documentary proof that I am now an official resident here in the Red Zone. There is no way for me to ever leave. I will stay here from now on, here in the Red Zone, walking with my grandmother's bones. But I will keep this unwanted and unwilled inheritance for myself. I won’t pass them on. When I no longer need them, whether buried, or cremated, or scattered and abandoned, or exposed to the elements on some bleak Red Zone mountainside, my grandmother’s bones will, as nature, physics, and impermanence dictate, crumble to dust. Just a little less slowly than most.