Hardy called it ‘dimmity’, the moment when the certain shapes of the world dissolve. In the emptiness of the Wessex marshlands, against the twilit mass of Glastonbury Tor, the air begins to quiver, to fill with dark scribblings. More than a million starlings are homing in on this ancestral swamp for their nightly communion. They stream in from every direction, joining, breaking ranks, floating free, like some black aurora. Suddenly, they become plasmic. They are one immense organism, pulsating like a single cell. They swing up to the sky and then skim the reeds in folds and falls of black. They fill out great parabolas and helixes, with a symmetry you do not expect from living things. Then, birds again, they fall into the reeds.

Spending the first half of my life in the Chilterns, in southern England’s chalk country, I grew up with yews. Not churchyard trees, but the bristly, mahogany-trunked nonconformists of the downs and beechwoods. They hunch among the grey-trunked beeches like dark Jack-in-the-Greens. Their seedlings, planted by thrushes, bristle impertinently on the hallowed chalk turf. Sometimes they grow into mature trees, but they never look old. They’re short and stocky. Their trunks are nondescript. Every gale and lopped branch and suggestion of rot leaves its mark on old oaks and beeches, in extravagant bosses and flares of muscled lignin. But yews look impermeable, islands of mute shadow in the woods.