Four mining ships are making the slow return to Mars from operations in the asteroid belt. Back on the planet, a group of students discover a mysterious object in space in an impossible orbit. The crew of the Lighthouse space station are shocked by a devastating accident that throws their routine into chaos as they strive to get their ships safely home.
Cut off from Earth, the sub-surface Martian Colony of New Providence suddenly finds itself in peril from something hostile and unknown. Is it alien? Is it an AI from Old Earth? After five generations enduring the harsh conditions on Mars, will the 50,000 citizens of New Providence survive this new and terrifying threat?