Four billion years, and the hand that once tore bark and pinned prey and dug tubers from frozen ground now presses, gently, one flat pane of glass, and waits for a spinning room to let it in.
We built that hand. The lungfish gave you the wrist. The shrew, hiding under leaves while the sky burned with things that wanted to eat her, gave you the fear that made you cautious, and here you are, cautious, timing your step into the turning glass so the panel does not clip your heel. Good. We approve. We do not know what it is for, but we approve.
Watch her: the one behind you, small, in her red coat, half your height, pushing the pane with both palms and her whole delighted weight, running the little circle twice before she comes out, spun and grinning, into the warm. We recognize that. The woman who kept the fire alive across the ice, who did not let it die once in her whole life, she ran in circles too, as a girl, before there was anything to guard.
We had forgotten that was allowed.
Do you understand what this is? A door that costs you nothing. That holds the cold out and the warm in and asks only that you push. No wolf on the far side. No winter waiting to take a finger. The man who buried the seed corn and slept hungry so the spring would have something to plant, he never once walked through a wall that kept the weather where it belonged.
You spend your Tuesday walking through walls that obey you.
We are the whole line, every survivor, and we are quiet now, all of us, watching you step out the other side into the heat we could barely imagine, unharmed, bored, ours.