Princess Ling Moy, a young and beautiful Chinese aristocrat lives next door, unbeknownst to her, to Dr. Fu Manchu, a brilliant but twisted genius who is out to rule the world. She is involved with Ah Kee, a handsome young man, who also unbeknownst to her, is a secret agent out to thwart the heinous plots of Fu Manchu. As it turns out, Fu is not only her next-door neighbor, he is also, (unbeknownst to her), her father. When she finds out, will she take her father's part and fight the men out to get Fu, or will she become a brave heroine and save the world even if it is from the devious doings of her own Dad? Yes, it's dated, and there isn't nearly enough of Warner Oland in it; but it moves along well, has a lot of action, Wong and Hayakawa were fine actors, and if you're a Charley Chan fan, it's worth it to how much, if any, of Fu Oland used when creating Charley Chan.