When Eugenia Insigna of the Settlement Rotor, an independent space station, discovers an unknown red dwarf star two light years from Earth, she names it Nemesis. Led by Dr. Janus Pitt, Rotor and its population travel to the star to build a new, morally pure society. Insigna's daughter Marlene, who can read body language like a telepath, learns that Nemesis is moving dangerously close to Earth's solar system. After trying to communicate her knowledge, Marlene discovers that a conspiracy is suppressing it. Told alternately from two points of view, Marlene's and (in a different time frame) her father's, the book is repetitive, talky and unengaging. Asimov is at his best when his characters discuss science and their schemes for saving Earth's people from destruction by Nemesis.