2019: NASA astronaut Nigel Walmsley is sent on a mission to intercept a rogue asteroid on a collision course with Earth. Ordered to destroy the comet, he discovers that it is actually the shell of a derelict space probe—a wreck with just enough power to emit a single electronic signal… 2034: A reply is heard. Searching for the source of this signal that comes from outside the solar system, Nige...