There's a little free library on my street. A wooden box on a post, holds maybe ten books. Last month I left my favorite book in it — the copy with all my notes in the margins. 'This line got me.' 'Nobody recovers this fast.' 'I'd forgive him too.' Today it's back. Same coffee stain on page 41. But under every note of mine, someone wrote back in blue pen. Under 'I'd forgive him too' it says: 'You would? I've been arguing with you about this for a month.' I don't know this handwriting. I check the street. Empty.

I take it home and grab a pen. Under their 'You would?' I write: 'Forgiving isn't the same as forgetting. Page 200 proves it.' I answer every single reply. Little arguments. Little agreements. On the last blank page I write: 'Your move.' Next morning I put the book back in the box. By noon it's gone.