An oil tanker burns at sea, and Molla Hansen, the captain's daughter, is the only survivor. Her rescuer, lighthouse-keeper Silas Martin, is fatally burned, and begs Molla to look after his daughter, Pearl. Meanwhile, Captain Rodney O'Malley, Molla's grief-stricken fiancé, departs on a long cruise. Two years later, Pearl is seduced by rum-runner Charley Watts, although she blames engineer Ira Meers. Molla learns of Pearl's pregnancy and holds Ira at gunpoint in the lighthouse. When Pearl discovers that Charley is already married, she locks him in the lighthouse tower, floods it with gas, and hurls a lighted lantern at him. Pearl and Charley are killed, but Ira recovers. The explosion signals Rod's ship, and he and Molla are reunited.—AFI