The exterior of the tower looked to be made of metallic panels-copper?-into which the builder had punched various imperfections, from bumps to indentations to holes. More unexpectedly, especially upon the first viewing, the tower twisted as it went up. What started as a rectangle at the base shifted as it rose until at the top it was a gravity-defying parallelogram. From the top-an enclosed viewing platform-Mickey had been pleased to recognize that the bottom of the tower was aligned with the east-west grid of the park, while the top’s orientation was turned to match the grid of the city’s downtown streets.

Inside now, he stopped a minute to listen to the jazz quintet playing in the lobby-a Friday-night tradition-then took the elevators up to the top. No charge. He’d been up here no fewer than forty times, and every time the place worked its magic on him. The windows were huge, both wide and tall, and through them the entire city revealed itself beneath and all around him. And since, because of the tower’s twisting nature, it wasn’t really obvious that there actually was a physical building under him, it always felt like he was floating.

The sun had just disappeared into the ocean and the purple western sky was now ablaze with gorgeous orange-red clouds. The Golden Gate Bridge was right there, just off to his right. And back behind him, the high-rises of downtown had just started to twinkle with their evening lights.

But tonight he wasn’t here for the views. Because of its parallelogram shape, the floor came to a point on both the north and south ends. Mickey looked left and then made his way to the corner, where, as he’d suspected and hoped, his sister-in a cowl-necked sweatshirt and camo pants-sat on the floor, apparently mesmerized, hugging her knees.

“They just let you sit here all day?” he asked.

She looked up and shrugged. “I’m not bothering anybody.”