The bridge had been rebuilt three times: washed away, collapsed, washed away again. The old mason said what everyone in that county expected him to say — that a bridge needs a foot to stand on. Bury a stone in the foundation with the name of a living person on it. Somebody willing.
A stranger passing through said he had nobody, and stood at the edge of the pit with his bundle at his feet while the chisel went in.
They dropped the stone in the trench and filled it. The bridge did not fall again. The stranger walked away the next morning over his own foundation and was gone by noon, and the village said the method worked, and the years went by.
Thirty years later the bridge wanted work again, and the mason who came was the old man's apprentice, grown and grey at the temples himself.
The spade hit stone about four feet down. He knelt and cleared the mud off with his sleeve, meaning to cut a new name into the same block and put it back.
The characters came up out of the mud one stroke at a time and he could not read them at first, in the way that you cannot read something you are not expecting.
It was not the stranger's name.
It was his own, cut thirty years ago, when he had been nine years old and holding the old man's tools.
He knelt in the mud at the edge of the trench with it in both hands for a long time. The stone had never recorded who paid. It had recorded who would come to dig it up.