41.8795° N, 87.8137° W. Come, see how the snow loops and hefts the lawns. It carves art from straight roads, narrows the lanes. Listen, my weight with each footfall: creak, crunch, creak. You can smell snow. It’s hard and pure, a palate cleanser. Snow-scent is the condition for the possibility of remembering smells. Mud in April, coffee, bus diesel. Oranges.

99kPa. I’m tired of the usual ways of knowing, tired of solus ipse. Walk with me. Let’s put our skin against it, against the half-dark edge of a square patch of forest, set between two international airports. Even so, it makes a horizon of cambric lace, threads of copper branches sewn against the sky. To the east, the horizon is exacted by rectangles. The Willis Tower’s iconic spires crown its hard shoulders.

4:32 pm CST. Here was someone with a sled, another with skis. Foxes and stotting ungulates. A pair of rabbits: the double skips, the two-footed leap, the scat like black buttons. A man and a dog blunder by us. Hello. Hey. Woof.

416.94 ppm. We know how it was, how it could have been, how Quercus ruled. Should we prepare for a hard living? The time of the oak savannah was first a glacial shift, followed by an Elysium of white pine, followed by this wind-blown plastic soda bottle clattering the toe of your boot. What should be our vision?

SiO₂. See that? Near the bottle, a rock. Mostly white with one tiny rust-red dot. We’re in a forest bordered by Washington Boulevard, First Avenue, the Metra tracks, and Thatcher Drive. There have always been ways to mark places, measure things, name them, to claim you know them. Now I’m tossing a stone up and down in my mitten, as if to learn. But it’s probably just a scrap of landscaping quartz from the homes on Thatcher.

2.9 × 10−8 kg. On the thumb of my black mitten is a single snow crystal. Then there are two. Then there are none. The deer blinks her obsidian orbits as we shift our weight.

1:12 am CST. The rewilding of these oak savannas could drown us, bury us. It could be ticks, EEE, Zika, black widow, brown recluse, poison oak and ivy, maple fungus, oak tumors, mad deer, murderers, a Des Plaines river flood, feral dogs. Sleep spirals galactically, finally, after an hour or so: how we die and are born a little, beyond ourselves. In my dream I walk on synthetic grass inside a lonesome high rise and wake up terrified, sweating.

11°F, but some bodies want the cold. I am one. I burn too hot these days.

2021 CE. In our narrow preserve of bare woods, let’s see if what they say of trees is true, even here. Maybe the expressway adds a low hush to their words, to their knuckled twigs sounding out the slightest knocks. Last year’s leaf is a stubborn chime. The accompaniment, the presence, the breathing: so it is true. Even so, I would miss you, walking alone.

623 ft. As we walk east, back to the city, I turn the stone over in my pocket. Our plain stone was a prism. All the roofs facing north are blue, and the roofs facing south are orange and pink. Icicles hanging three to four feet are jagged and striped liked candy. Winter is a teacher. We are alive. The last flame of this day’s sun ignites a cloud’s red edge. Its wisps and curls are round and wild— a blazing indifference to endings.