_Frankenstein_ is one of those novels that defy the critic. Everyone recognises that the letters written by Captain Walton to his sister in which he tells of his meeting with Frankenstein, and repeats to her the story he has just heard from his guest, makes an awkward introduction to the real narrative. Yet all this part about Captain Walton and his crew was added at the suggestion of Shelley after the rest of the story had been written. But the narrative of Frankenstein is so powerful, so real, that, once read, it can never be forgotten. Mrs. Shelley wrote in the introduction of the edition of 1839 that, before writing it, she was trying to think of a story, "one that would speak to the mysterious fears of our nature, and awaken thrilling horror--one to make the reader dread to look round, to curdle the blood and quicken the beatings of the heart." That she has done this the experience of every reader will prove. But the story has a greater hold on the imagination than this alone would give it. The monster created by Frankenstein is closely related to our own human nature. "My heart was fashioned to be susceptible of love and sympathy," he says, "and, when wrenched by misery to vice and hatred, it did not endure the violence of the change without torture, such as you cannot even imagine." There is a wonderful blending of good and evil in this demon, and, while the magnitude of his crimes makes us shudder, his wrongs and his loneliness awaken our pity. "The fallen angel becomes a malignant devil. Yet even that enemy of God and man had friends and associates in his desolation; I am quite alone," the monster complains to his creator. Who can forget the scene where he watches Frankenstein at work making for him the companion that he had promised? Perhaps sadder than the story of the monster is that of Frankenstein, who, led by a desire to widen human knowledge, finds that the fulfilment of his lofty ambition has brought only a curse to mankind. In 1823, Mary Shelley published a second novel, _Valperga_, so named from a castle and small independent territory near Lucca. Castruccio Castracani, whose life Machiavelli has told, is the hero of the story. The greatest soldier and satirist of his times, the man of the novel is considered inferior to the man of history. Mrs. Shelley had read broadly before beginning the book, and she has described minutely the customs of the age about which she is writing. Shelley pronounced it "a living and moving picture of an age almost forgotten."