Please answer the following question: Build a movie plot around this: Who visits Dr. Julian Karswell? Professor Harrington.
Answer:
In England, Professor Harrington (Maurice Denham) visits his rival, Dr. Julian Karswell (Niall MacGinnis). Harrington promises to cancel an investigation of Karswell's involvement in Satanism if Karswell will rescind a threat he has made against Harrington. After learning that a parchment given to Harrington has disintegrated, Karswell glances at the clock and ushers Harrington out, promising to do all that he can. As Harrington drives home, a gigantic demon materialises and pursues him. Losing control of the car, Harrington crashes into an electrical pole and is electrocuted.Dr. John Holden (Dana Andrews) arrives in England to attend a convention at which Harrington had intended to expose Karswell's cult. Holden is informed of Harrington's death and that the only link between it and Karswell's cult is an accused murderer, Rand Hobart (Brian Wilde), who has fallen into a catatonic stupor. While Harrington's collaborators consider the possibility of supernatural forces, Holden rejects the idea as superstition.Following Harrington's notes, Holden visits the British Museum's library to examine books on witchcraft. A book Holden requests is discovered to be missing. Karswell offers to show Holden his own copy at his mansion. At Harrington's funeral, Holden meets the dead man's niece, Joanna (Peggy Cummins), who gives him Harrington's diary. It reveals Harrington's increasing fear of Karswell's power. Holden remains sceptical, but goes with Joanna to Karswell's mansion the next day.There, Holden and Karswell mock each another's beliefs. A very strong windstorm abruptly starts, which Karswell claims to have created with a spell. When Holden continues to mock him, Karswell grows angry and predicts that Holden will die in three days.Holden and his colleagues discuss Karswell and make plans to further examine Rand Hobart. Harrington's diary mentions the parchment passed to him by Karswell; Holden finds a parchment with runic inscriptions that Karswell secretly passed to him at the library. Powerful winds come...