 Two novels suggested as inspirations for "The Thing on the Doorstep" are Barry Pain's "An Exchange of Souls" (1911), about a scientist's invention that allows him to switch personalities with his wife, and H. B. Drake's "The Remedy" (1925; published in the U.S. as "The Shadowy Thing"), in which a character with the power of mind-transference comes back from the dead by possessing the body of an injured friend.Peter Cannon wrote two sequels to "The Thing on the Doorstep"