"Satan" Humphrey is the captain of the tramp steamer Glory Ann, is killed during a mutiny. His daughter Paula, brandishing a pistol, holds the mutineers at bay. Not long afterwards the ship picks up John Hadlock, an injured shipwreck survivor. Paula nurses him back to health and falls in love with him. John, recovering, helps her control the mutinous crew. The ship stops at San Francisco to pick up Glory, Paula's sister whom she hasn't seen since birth. As the ship sets sail for the South Seas, however, the crew mutinies again. Complications ensue.