White chalk cliffs of Britain's southern coast. Chalk is layers of skeletons of tiny ancient dead sea creatures, packed down, from when this whole landscape was underwater whatever millions of years ago.

One thing about chalk: it’s the great insulator. Walk the chalk even in blackness and feel yourself swaddled from the crackle in a great safe tunnel. If you’re attuned to these things—and some people are and were—you close your eyes and use your nose, as they used to say, and flow through the chalk and know at once if other creatures are near or if you’ve strayed off-path. Feel the land inside you.