The ancient moralities and worldviews of established religions and the ruling majorities of Earth's most powerful nation-states have been fighting a rearguard action against the encroachment of science on what they consider to be the core of the human self: its mind and consciousness. The United Nations Human Genome Protection Act has outlawed all genetic enhancements of human offspring, and the old contenders for world domination, the United States and China, have allied themselves to destroy all conscious nonhuman operating units in every outpost of civilization. Set in such a world, Human Sister is the story of a prodigy, Sara Jensen, the granddaughter of Professor Severn Jensen, one of the world's leading experts on conscious artificial intelligences, who, with his wife, raises and homeschools Sara on their beautiful California vineyard. Sara's family also includes a secret fourth member-her illegal bioroid brother, Michael, whom she helps raise and who was made by her grandfather in part from Sara's neurons and other cells and who is capable of accessing her thoughts and affections. Amidst a dangerous and darkening outer world, Sara discovers that she also must contend with the secrets and deceptions of those she loves-her grandfather, her boyfriend, and Michael-and she learns that even the best of intentions diligently pursued often have unintended, and tragic, consequences.