Demon of Darkness. He had the face of Lucifer and a soul filled with evil. And he had sworn that lovely young Sally Lane would die if she revealed his presence on the Landsdown estate to anyone. Was he a man or a demon? Sally didn't know or care. She only knew that he could mysteriously appear anywhere at any time, even in the Landsdown mansion itself! And she knew that whatever diabolical purpose had brought him there, no one could save her -- not her wealthy employer, Martin Landsdown, nor his handsome nephew Scott, who loved Sally and would do anything to protect her -- if she betrayed this evil stranger. So Sally kept her silent vigil of fear, little realizing the terrible doom her silence might bring upon everyone in THE HOUSE OF LANDSDOWN.