With his powers of hypnosis, the cruel music teacher Svengali (John Barrymore) is able to control women. When he sets his sights on the beautiful Trilby O'Farrell (Marian Marsh), she falls under his spell -- but her true love, Billee (Bramwell Fletcher), won't be taken easily out of the picture. Though Svengali gets the golden-voiced Trilby to fake her death, and then brings her on a tour of Europe, Billee uncovers the deception and sets out to wrest her from Svengali's clutches.