William Hails Street Books for Curbside Service

I wasn't quite sure, but as I was pedaling through Old Town, I thought perhaps this fellow was flagging me down.  He was a block and a half away and waving his arms all the while moving toward me.  I made my way over to him and sure enough, he was flagging me down.  "I have some books to return to you," he said.  He traded two fantasy books he had borrowed last week for two more.  Plenty more where those came from.  See you next week, William!