In the 22nd century, humankind has colonized the solar system. Starflight is possible but hugely expensive, so humakind's efforts are focused on Isis, the one nearby Earthlike world. Isis is verdant, Edenic, rich with complex DNA-based plant and animal life. And every molecule of Isian life is spectacularly toxic to human beings. The entire planet is a permanent Level Four Hot Zone. Despite that, Isis is the most interesting discovery of the millennium: a parallel biology with lessons to teach us about our own nature. It's also the hardest of hardship posts, the loneliest place in the universe. Zoe Fisher was born to explore Isis. Literally. Cloned and genetically engineered by a faction within the hothouse politics of Earth, Zoe is optimized to face Isis' terrors. Now at last Zoe has arrived on Isis. But there are secrets implanted within her that not even she suspects—and the planet itself has secrets that will change our understanding of life in the universe. Bursting with ideas, replete with human insight, Bios is science fiction in the grand tradition: a novel of bravery, exploration, and discovery in a universe charged with awe.