When Nigel Walden is 14, the Unhappenings begin. His first girlfriend disappears the day after their first kiss with no indication she ever existed. This retroactive change is the first of many only he seems to notice. Several years later, when Nigel is visited by two people from his future, he hopes they can explain why the past keeps rewriting itself around him. But the enigmatic young guide shares very little, and the haggard, incoherent, elderly version of himself is even less reliable. His search for answers takes him 52 years forward in time, where he finds himself stranded and alone. And then he meets Helen. Brilliant, hilarious, and beautiful, she captivates him. But Nigel's relationships always unhappen, and if they get close it could be fatal for her. Worse, according to the young guide, just by entering Helen's life, Nigel has already set into motion events that will have catastrophic consequences. In his efforts to reverse this, and to find a way to remain with Helen, he discovers the disturbing truth about the unhappenings and the role he and his future self have played all along.

Equal parts time travel adventure and tragic love story, Unhappenings is a tale of gravely bad choices and Nigel's struggle not to become what he sees in the preview of his worst self.