Not so long ago James Mangan was a brilliant young poet. These days, however, he toils as a journalist and shivers in the shadow of his glamorous movie-star wife. And now she has left him for her lover. Adrift and depressed, Jamie takes refuge with his father, in whose house he turns up a 19th-century daguerreotype bearing the initials 'J.M.' and depicting a man who, as it happens, is Jamie's splitting image. Could this be the only existing photograph of his purported ancestor, the legendarily dissolute Irish poet James Clarence Mangan?