Through hypnotism and telepathic mind control, a sinister music maestro controls the singing voice, but not the heart, of the woman he loves.

Sinister music maestro Svengali (John Barrymore) can control the actions of women through hypnotism and his telepathic powers. When a pupil (Carmen Myers) he seduced announces she has left her husband for him, he uses his powers to cause her suicide and promptly forgets her. He meets beautiful model Trilby (Marian Marsh) and becomes infatuated with her, but she falls for young artist Billie (Bramwell Fletcher), who also loves her. One day, Svengali hypnotizes Trilby to cure her headache, but also examines her upper palate and decides it is an ideal cavity for great singing. He convinces her to fake her suicide, so Billie and friends will forget her, and goes on a singing tour with her. Svengali uses his powers to make her sing wonderfully and Madame Svengali, as Trilby is now known, becomes a sensation throughout Europe. But Billie discovers the ruse and follows the pair, upsetting Svengali enough to have him cancel performances too frequently, so they can no longer perform in Europe. They go to Egypt, but Billie relentlessly follows.—Arthur Hausner <[email protected]>

Svengali (John Barrymore) is a singing teacher, pianist and general music impresario living in Paris. He has special talents: he is able to mesmerize others through his music and through his strong hypnotic powers. He uses these talents specifically to seduce his female students for his own evil monetary gains. He discards them just as easily when they are no longer of use to him. After he hears her sing (she isn't the greatest) and sees her, Svengali becomes infatuated with young model Trilby O'Farrell (Marian Marsh) whom he meets in the studio of some artist colleagues. One of those artists, young Brit Billie (Bramwell Fletcher), and Trilby fall in love and plan to marry. But after Billie and Trilby have a falling-out of sorts, Trilby runs away apparently to commit suicide. Concurrently, Svengali disappears. He resurfaces five years later, married to his singing protégée, who performs with him in concerts. Billie learns that Madame Svengali is Trilby and vows to follow the pair to save Trilby from whatever special power Svengali holds over her. Knowing that Billie is after them, Svengali has his own plans for his and Trilby's eternity.—Huggo