We discover a new species of life form every day. But, every day, a species also disappears. The fly has 10 chromosomes, the hamster 22, the rat 42, the human 46, the chimpanzee 48, the cow 60, and the butterfly 380. London, 1881. There's something a little eerie about Manon – she's not like the other girls at the orphanage. Maybe it's her red eyes. Maybe it's her silence. Maybe it's the series of violent deaths that seem to follow her. What we do know: someone is hot on her tail. And there's a lot of money at stake in finding out where exactly she comes from – and what exactly she is. Concurrent to Manon's story are letters to Charles Darwin from Professor Humphrey, a scientist who has recently died under mysterious circumstances. Is it true that natural selection left humans at the top of the pyramid of life after all? Or in the process of evolution, was there something elemental that humans lost, something that connected us to the rest of life on earth? Who and what else is out there? In order to stay alive, Manon must untangle the mystery of her origins, and perhaps the origins of humanity as well.