When Judy Corbett caught sight of a great stone mansion in the craggy wilds of north Wales, she had little idea of the adventure on which she was about to embark. She and her husband, Peter, had long dreamed of buying an old ruin and escaping the pace and excesses of modern life. But it was only when they had moved into the vandalized, squalidly filthy, cold and wet Gwydir Castle that they began to realize what restoration dramas lay ahead. Restoring the 16th-century castle, which reduced the couple to near penury, turned their lives into a curious blend of real and imaginary, past and...