(i) A good way to waste a day is to lay in a field, looking up at the blue, unbroken sky. If you pick the highest ground, you can be lost in the grass or wheat or barley or whatever without anyone looking over you and disturbing your peace. Otherwise, it’s just you and the sun and maybe the occasional bird or buzzing insect.
(ii) I walked to this field quite often. It has a long barrow. It wasn’t more than a couple of miles, but it might have been 1000 years away from the house. It’s remarkable how near you can be to the present, and yet not being able to see the buildings and pylons and streetlights makes it feel so long ago. I liked this particular place because it was all those things. The furthest corner was at the top of a gradual and gentle incline, so chances of getting found were slim. The field was wheat, so the planting was tall. You could skip through the houses down a path through the hedges and trees - effectively disappearing at the edge of the estate, and not reappearing until you were close to your final destination, a whole other place and time. Just past the Fiveways junction, where you might leave your offering to Hecate, the three-faced goddess of boundaries, crossroads and ghosts. If you were inclined. Perhaps she’ll keep the dead ones from coming through.
(ii) There was a long barrow, built three and a half thousand years before Christianity, and storing bodies, parts of bodies and the occasional stone pot. Great dolmens held up the earth as chambers were raised and changed over centuries of use. Those that built the barrow knew. Often the bodies were separated so that similar parts could be kept together - a chamber of skulls, a chamber of chests, a chamber of limbs. Often, the bodies were excarnated, left naked for the flesh and fat to fall away, perhaps just laying outside for everyone in the World to see. Waiting until the next auspicious moment, when the barrows would be opened and the contents reorganised - new bodies, new parts of bodies. Some bodies weren’t left in the barrow. Some, perhaps, were removed from the barrow and left elsewhere. Some, perhaps, removed themselves. Long barrows could be extended so there was room for more - remember, these people didn’t live to ripe old ages. If you survived to 15, you might live to 30. If you survived to 15. So I imagine that there was always a need to extend, to make room for another generation of relatives. Down into the barrow, dig out a new chamber, move the old bodies, get the new bodies, parts of bodies. And no doubt this work had to be done at exactly the right time.
(iv) Do we know when the right time was? I think we can guess. Perhaps when the skin between the world of the living and the world of the dead was most permeable. You might be able to visit your ancestors, to talk to your parents, to hold your dead children. So a small tear might be all you needed, as long as you stitched it up as you returned. If you returned. And Hecate would let you back.