"Don't be alone, Doctor," Amy Pond tells the Eleventh Doctor in "The Angels Take Manhattan," and of course the irony is that in one sense the Doctor is always alone—a Gallifreyan whose regenerative powers mean he will outlast nearly everyone near and dear to him — while at the same time he is rarely without one or more trusted companion by his side. This is a book about those companions—those fortunate few who accompany him on his journeys through space and time on—to quote the Ninth Doctor—"the trip of a lifetime." The editors of The Villains of Doctor Who are back with a new anthology of essays—paeans, really—to Donna Noble, Sarah Jane Smith, Rose Tyler, Wilfred Mott, Chang Lee, Clara Oswald, and more. Did your favorite companion make the cut? You're going to have to read to find out!