Shannon Moss is part of a clandestine division within the Naval Criminal Investigative Service. In 1997, she is assigned to solve the murder of a Navy SEAL's family, and to locate his teenage daughter, who has disappeared. Moss discovers that the missing SEAL was an astronaut aboard the spaceship U.S.S. Libra--a ship assumed lost to the darkest currents of Deep Time. Moss knows first-hand the mental trauma of time-travel and believes the SEAL's experience with the future has triggered this violence. Determined to find the missing girl and driven by a troubling connection from her own past, Moss travels ahead in time to explore possible versions of the future, seeking evidence or insight that will crack the present-day case. To her horror, the future reveals that it's not only the fate of a family that hinges on her work, for what she witnesses rising over time's horizon and hurtling toward the present is the Terminus: the terrifying and cataclysmic end of humanity itself.