Environmental scientist Constance Roy is one of forty-nine refugees rescued from Earth's destruction and transported to the ark spaceship Orb by an automaton race called the Curators. Twelve months have passed since their rescue. But now, with the ship's orbit decaying, the refugees seem doomed to crash into Jupiter's fiery belly. In a parallel universe on present-day Earth, another version of Constance seeks answers to the questions that have haunted...