James Tiptree, Jr., burst onto the science fiction scene in the late 1960s with a string of hard-edged, provocative stories. He was hailed as a brilliant writer with a deep sympathy for his female characters. He carried on intimate correspondences with other writers, none of whom knew his true identity. He was so reclusive that he was widely believed to be a top-secret government agent. Then the cover was blown--on a sixty-one-year-old woman named...