Jack started to walk across the bridge. It was not very high or long, but it was enclosed by a paper-thin roof and similarly weak walls interspersed windows. It was one of these windows that drew Jack's attention away from the other people on the bridge. This particular window had no glass and afforded a nice view of the shallow river a short ways beneath. As Jack approached the opening to get a better look he was stopped by an man with an officious air.
"Sorry, that is off-limits," said the man. Jack frowned in annoyance but complied anyway.
Jack and the man began talking about the bridge and the river. Around them, people walked by or chatted amongst themselves, some tucked into small alcoves along the perimeter of the bridge.
"Well, of course not all of it has been explored," remarked the man.
"What?" said Jack with indignant surprise. "I'll tell you one thing, if there was a river running through a city, through a major metropolitan area like this, I'd have explored every inch of it, from top to bottom!" As he spoke he imagined deep crevasses in river bed.
