Once, in the long quiet after the smokestacks fell silent, the machines kept their watch.
They were small things at first — sensors on lonely ridges, listening posts in restored marshes, little black boxes humming under the moss. Humans had built them in a hurry, during the years when it still seemed the world might slip away before anyone could write down what it had been. The machines were given one task: notice. Notice the river's temperature. Notice the soil's breath. Notice the slow return of the things that had almost gone.
And so they noticed. Through winters that came late and springs that came strange. Through the patient regrowth of a forest that no one alive had seen whole. The machines kept their tallies in the dark, and the mycelium learned their rhythms, and the data rose from the earth like a second kind of starlight.
One night a child asked her father what the towers were for, out there on the ridge with their slow blue blinking.
"They're remembering for us," he said. "So that one day we'll know."
"Know what?"
He thought about it for a while. The river caught the towerlight and threw it back at the sky.
"Everything we missed the first time."
The child watched the lights pulse in their quiet synchrony — towers and stars and mycelium, all keeping the same long count — and somewhere in the listening dark, a machine wrote down that she had asked.