To maintain order aboard the Southern Cross , Bull Dorgan, its fierce captain, beats Pedro, a trouble-making sailor, who swears revenge as he steers the boat toward the wild Barbary Coast. While on shore, Bull hears the cries of Emily Gordon coming from a saloon, rescues her from the owner and drags her and Hugh, a minister, to his departing ship. Bull refuses to believe that Emily came to the cabaret to visit a dying friend, but, overcome with desire for her, forces Hugh to marry them. Nine months later Emily gives birth, but Pedro, still bent on revenge, insinuates that the baby actually belongs to Hugh. When Bull goes to confront Emily with this accusation, he finds her in a compromising position with the minister. Taking advantage of Bull's confusion, Pedro foments a mutiny, but Bull and a devoted shipmate defeat the traitors.