Cryptogram from Frankenstein; or, the modern prometheus, chapter 24

His tale is connected and told with an appearance of the simplest truth, yet I own to you that the letters of Felix and Safie, which he showed me, and the apparition of the monster seen from our ship, brought to me a greater conviction of the truth of his narrative than his asseverations, however earnest and connected. Such a monster has, then, really existence! I cannot doubt it, yet I am lost in surprise and admiration. Sometimes I endeavoured to gain from Frankenstein the particulars of his creature's formation, but on this point he was impenetrable.

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Frankenstein discovered that I made notes concerning his history; he asked to see them and then himself corrected and augmented them in many places, but principally in giving the life and spirit to the conversations he held with his enemy. "Since you have preserved my narration," said he, "I would not that a mutilated one should go down to posterity."