The once-mighty Biograph company effectively drove another nail into its coffin by securing the motion picture rights for the hoary old stage melodrama Under the Gaslight. Heroine Laura suffers spectacularly from first scene to last, as her romance with her soldier sweetheart is destroyed by malicious gossip. The villain of the piece is Bykes, who for mercenary reasons claims that Laura, an heiress, is actually his own daughter. In concert with his partner-in-crime Mrs. Bykes, the double-dyed heavy makes life miserable for everyone concerned, but by the time the final curtain rolls down, everything is set aright. Under the Gaslight is famous as the play that introduced the cliched "thrill" device of having the villain tie someone to the railroad tracks -- only in this case, it was the hero who was lashed to the tracks, and the heroine who ultimately saved him.
by Hal Erickson synopsis