History is a pendulum in the shape of a mallet.

From Alfred’s journal

A man on the bench by the library was reading a newspaper from 1968 on his telephone, and he read parts of it aloud to nobody, laughing at how familiar it sounded. For years I thought the swinging was the whole of it, that things went one way and then came back and nothing was lost in the trip. Then the clock in the library tower struck noon and I watched the pigeons come off the ledge all at once, the way they do when something hits them from above rather than beside. History is a pendulum in the shape of a mallet. The man folded the telephone away and said, well, here we go again, and he was cheerful about it. I have been trying since to work out whether he had been hit before or only watched.