The story of the human race is a story of technology. One of our ancestors created fire and passed that knowledge along to the next generation. Then the invention of the wheel. Then agriculture, a writing system, mathematics, space travel. Within our story, empires rise and fall. Technology progresses. Civilizations are born and die. The human race continues to innovate. All of our innovations are built on previous ones. There could be no aqueduct without the arch. There could be no metal plow until someone learned how to mine iron. There could be no light bulb, no smartphone and no computer without first understanding electricity. Our progress is linear. But sometimes an object is discovered that's completely out of place and out of time. A computer found on a sunken Roman ship. A power plant found in a 100,000-year-old cave. Evidence of a nuclear reactor from over a billion years ago. These objects shouldn't exist. But they do. So if humans didn't create these items, who did?