Federal Judge Folger accuses two Wall St. speculators of manipulating the stock market because of their knowledge of a solar-power machine being perfected by Professor Farrington. He goes the Farrington's mountain lodge, The Crag, to investigate. Danny and Farrington's daughter, Doris, are also heading there to get Farrington's consent to get married. They take along a married couple, Gertrude and Freddie, as chaperone's. Farrington's servants include a spooky housekeep and her even-spookier son, Henry. Doris and her companions arrive to find that Folger has been murdered and her father is missing. Freddie partakes of some bootleg whiskey his finds and goes on a search; he finds the professor's body in another room and that of Henry in a closet. He informs Danny but when they return both corpses have vanished.