One morning, my uncle arrived at his family medical practice in Toledo, Ohio, to find threats on his answering machine. A muffled voice greeted him with a string of expletives before warning that there would be consequences if he didn't "get the hell out of here." In the 30 years since Uncle Doctor, as I called him, had emigrated from Pakistan to the United States, he had never been singled out for his nationality or religion. It was September 12, 2001, and the dust still hung heavy in Lower Manhattan. A similar message was waiting for him at home. "The scariest thing about it," my Aunt Kathy says, "was that whoever left those messages knew us. They knew our names. They knew the clinic number and our home number, even though it was unlisted." Today, my aunt and uncle struggle with the details ("It was ten years ago!" my aunt says), but at the time, they felt it was necessary to report the threats to the FBI. A middle-aged agent arrived on their doorstep clad in jeans and a khaki...