Two weeks in the Amazon, all expenses paid, the kind of trip a man in his thirties never expects to win. Mike Doucet won it for being top seller in his Verizon district. He took his wife Sarah, a Tulane neurobiologist, because they had not been on a real vacation in six years.The lodge sat on a black-water oxbow lake the locals called Cocha Negra. The owner was an American expat who smiled too long and kept his coffee cup at the same angle every time he set it down. The village down the trail had a fever going around, and nobody there could explain it. Six weeks earlier a Petrobras survey crew had run seismic charges on the lake bottom and left.Sarah figured out the fever was not a fever. The microscope she always packed told her that what she was looking at was not anything that had ever lived on this planet. By the time she said it out loud, Mike had already met the old man at the village who knew what was sleeping at the bottom of the cocha. By the time they tried to leave, it was too late to leave the way they had come in.The virus beneath Cocha Negra came home with them