In the early 1990's novelist Alan Lightman published "Einstein's Dreams". In it he described the great physicist's dreams as he worked out the theory of relativity. It was a smash hit, selling 600,000 copies. Lightman's new novel, "Reunion" also deals with the workings of the mind. But this time it's the mind of Charles, a middle-aged and somewhat mediocre professor attending his college reunion. He finds himself thinking back to his love affair with a ballet dancer during his senior year. Charles begins to realize the story says more about him than perhaps he's ever acknowledged. Alan Lightman told Minnesota Public Radio's Euan Kerr he was interested in how people construct their identities, and sense of being from all the little pieces of their pasts.