"When San Francisco's landmark Emporium department store was gutted in 2003 to make room for the Westfield San Francisco Centre, the most spectacular feature of the site was its old dome, supported on a tower during construction after being hydraulically jacked into the air 60 feet above its original location in space. But a few hundred feet to the southwest was a wall covered with shredded wallpaper, bearing the imprint of former floors and walls, that came to life in the slightest breeze. I no longer remember what took me to that part of town in those days, but the sight transfixed me."