A Man of Two Minds
From Tardis Wiki, the free Doctor Who reference
A Man of Two Minds was a novel written by Jackson Lake and published in 1860. It featured "the Doctor", "Mr Smith", and the Cybermen. Though ostensibly fictional, many speculated it was actually an autobigraphical account of Lake's true experiences. (PROSE: The Secret Lives of Monsters) Jackson Lake did in fact have a period where he believed himself to be the Doctor and encountered the Cybermen. (TV: The Next Doctor) The alientologist Justin Richards included an excerpt from the novel in his alien exposé The Secret Lives of Monsters. (PROSE: The Secret Lives of Monsters)
