Threshold

That evening the signal came in words.

They had made camp on a bench of ground above the foothill town, the circled town, though from up here it was hard to believe a thing so ordinary had been the whole engine of her crossing the world. It sat in the mouth of a canyon where the mountains let down onto the plain, a few streets, a water tower, a scatter of roofs going back to the earth, and a squat brick building on the near edge with a lattice tower rising off its roof, and it was from the tower, she knew before Eli said it, that the pulse had been coming all along.