The viewpoint character chats with another character, often a friend or associate, whose ideas seem almost too outlandish to believe. Nevertheless, the seeming crackpot is actually Mr. Exposition and will be vindicated by the story. The exposition doesn't need to be of any practical use to its hearer; its main purpose is to make the strange happenings in the story easier to understand and more plausible for the reader.
- Type One: After explaining the theoretical background the character proceeds to give evidence. The evidence may be a material object or a story about how he learned what he now knows, for which the discussion is a Framing Device.
- Type Two: After the explanation, the character proceeds to test out his theory in practice. The experiment will provide results, but may turn out to be more dangerous than the character expected.
- Type Three: After the explanation, the hearer proceeds to bump into the evidence by sheer coincidence.
- The White People by Arthur Machen. Ambrose has strange ideas about the nature of true sin as violation of the laws of nature and lends the main character a manuscript written by a girl who had supernatural experiences.
- The Devotee of Evil by Clark Ashton Smith. The main character becomes an acquaintance with a man who believes evil to be an universal force and is developing a mechanism to show it in practice.
- The Tomb-Spawn by Clark Ashton Smith. A story-teller tells the main characters of an ancient wizard-king and his tomb and how the tomb has been prophesied to be found accidentally. The main characters' later experiences show that the story-teller was perfectly accurate.
- Eloi Eloi Lama Sabachthani by William Hope Hodgson. The narrator's friend believes in the historicity of the Gospel narrative and prepares an experiment to show that the darkness when Jesus was crucified is both scientifically possible and proof of Jesus's exceptional soul.
- The Derelict by William Hope Hodgson. A ship's doctor talks about a mystical life-force and then continues to give an account about a living derelict.
- "The Time Machine"
- In My Little Pony Friendship Is Magic, When Twilight investigates ancient folklore, naturally there is immediate proof it was true.
- Real Life example: The computer.
- Another one: The positron. In this case, the gap between theorizing and exposition is as long as 4 years.