On her deathbed, an aged woman recluse promises to repay young siblings Dorothy and Bobbie Carleton for their friendship. During the Galveston tidal wave of 1900, the children are separated. Bobbie is adopted by a surgeon, Dr. Richard Stanton, while Dorothy, suffering from amnesia, is adopted by Captain Smith. Two years later, Bobbie, now called Robert, visits the country and rescues Dorothy, now called Blanche, from an attacker. Six months later, while taking food to needy people, Dorothy is attacked by tramps in a deserted shack. An unseen spirit tips the candle lighting the room, and Dorothy escapes. Robert, nearby, feels an urge to go to his window. Seeing Dorothy running, he thrashes her pursuers. Later, in New York, Dorothy's clothes catch fire as she decorates a jack-o'-lantern for Halloween. Robert, now Stanton's partner, saves her. They fall in love and plan to marry, but as he is about to sign the marriage contract, Robert, because of a spiritual force, is moved to write that Dorothy is his sister. He examines a scar on her leg to confirm this, and the catastrophe is averted.