To save her father from suicide and disgrace, Stella Everett consents to marry Robert Crane, a wealthy politician, and breaks her engagement with Frank Mansfield, Crane's rival for congressional honors. Crane has ruined a young gypsy girl named Mary, and her mother, Zenda, known as the Woman in Black, seeks him to avenge the wrong. Chancing to see a campaign poster bearing Crane's picture, she plunges a dagger into it as Mansfield passes by. Puzzled by her action, he learns her story, and brings the two gypsies to Stella, who is to marry Crane next day. Everett, hearing the facts, is about to call the marriage off, but the Woman in Black proposes a scheme. The marriage takes place as arranged, and Crane, lifting his bride's veil, uncovers the face of Mary, the girl he wronged. Zenda buries the dagger in his heart. Mansfield is elected to the office and marries Stella.
—Moving Picture World synopsis