Like many novelists, I’m interested in the gaps and ghosts in the historical record, the people who flit through the background leaving the scent of untold stories on the air, the events for which the evidence is fragmentary. Prehistory feels different. Prehistoric experiences are by definition untold, but people were – probably, maybe – so different then, their experiences so far from and perhaps irrelevant to ours, that most readers and writers don’t go there much.
 
But prehistoric lives have always fascinated me. I knew from childhood that literature was my first love, but I wish I’d been educated in a system that let me study more than one subject because I’d have done archaeology too (and textile arts, and ceramics, and biology, and human geography and history and lots of languages, Italian and Greek and Japanese). One of my early memories is finding a nicely-weighted flint with a sharp edge near the top of a mountain in the Lake District and insisting that it was a prehistoric hand-axe and we should take it home with us; my parents later let me take it to an open day at the Manchester Museum where a curator confirmed my story. I remember holding it, hefting it, thinking about the hands that had made it and the fingers that had rested where mine were. 
 
I spent several childhood summers with my grandparents on the Orkney islands, where in those days all the prehistoric tombs and chambered cairns were fenced to keep the cattle out but otherwise open to anyone at any time. I used to wriggle through the low doorways and climb down into the dark hollows where bodies had lain for centuries, often with strange company: dead eagles and dogs, jewelled swords, pots of grain. I was afraid of what was (not) there, and drawn by the physical proximity of these unknowable lives and deaths. I returned as a teenager, roaming further, pacing around standing stones and trying to intuit the geography of people who were like us and yet utterly unlike us.
 
The fascination persists, shaping my new book Ghost Wall. Foundation myths live in prehistory, back just before the inconvenient truths of the historical record, and foundation myths feel very relevant at the moment. I live in a country where xenophobia and nativism have become normal in the last couple of years, where the rights of people perceived not to be British, or not British enough, are routinely denied.  If the legal right to a British passport doesn’t make you ‘British’, what does? Is it enough if both your parents were born here? How far back do you have to go? The idea of hereditary nationality is odd, mixing blood and land in a way that you’d think we’d know can only end badly, and yet here we all are, many British passport holders scrambling around in our attics trying to find Granny’s Irish birth certificate or some proof of great-grandpa’s loss of citizenship in World War Two, while others who have lived and worked and paid taxes and raised children here for decades are more desperately scrambling for evidence that they should be allowed to stay. That question from two years ago, to leave or remain, who is in and who is out, takes personal and violent form in houses, streets, schools and hospitals across Britain.
 
We’re told that those who wanted to leave the EU two years ago now want everyone else to leave Britain (I suspect it was more complicated than that). In this story, the country was better before the immigrants came, when all the inhabitants were native British. When, I wonder, was that? Before the Windrush? Before the Empire brought people from India and Ireland and parts of Africa to live and work in Britain in the nineteenth century? Before the transatlantic slave trade? Before William and Mary came from Holland to rule us? Maybe before the Norman Conquest, before all those French people brought wine and made us stop speaking Anglo-Saxon? No, because the Angles and the Saxons came from the Nordic countries via France (Saxony, in fact). Before the Anglo-Saxons we had the Romans, bringing underfloor heating and literacy but definitely not British and not even, actually, very Roman; there were Syrian and German troops in Yorkshire and Northumberland two thousand years ago, coming over here and making the roads run straight. And writing things down: there were runes and bits of script before the Roman conquest of Britain but our historical record begins with the arrival of those foreign troops. The ‘Britons’ who experienced that invasion had come, a few generations earlier, from Ireland and Brittany (Britain is named after part of France), their material culture distinctively Celtic. There were people in these islands before the Celts came, and they left some stones and bone fragments, just enough for us to know that they, too, came from elsewhere. 

Go back far enough and we all came out of Africa, or Eden if you prefer a foundation myth to archaeology. Either way, according to the logic of national blood, none of us belong on these islands.