A stone - like that thrown at us, and from the same place. There's no lack of more stones, children to throw them, or reasons.

I remember the occasion well. We were on the outskirts of a village and a group of kids "accompanied" us. We felt sort of like the Pied Piper of Hamlyn, with kids joining us with every step we took. Only one or two stones were thrown, but they made their point.

I picked one up for saving. It probably wasn't the stone.