James Gordon, Sr., owner of the Gordon syndicate, dispatches his roughneck son Jimmy to investigate why production has fallen off in his opal mine on an island off the coast of lower California. After an argument with his fiancé, socialite Lucy Andrews, Jimmy leaves for the island where he is met by Juan, McCool's servant who, along with Jasper Sneedham, has been cheating the company. On the launch, Juan tries to eliminate Jimmy by hitting him over the head, but escapes and swims to shore where he is rescued by Sneedham's stepdaughter Nadine. Nadine takes Jimmy to the hut of mine foreman Fred Haimer, the only honest man on the island. When Nadine overhears her stepfather's plans to take his ill gained fortune and flee, Jimmy and Haimer team up to defeat Juan, Sneedham and McCool. After a number of grueling skirmishes, Jimmy, Haimer and Nadine escape to the mainland where they notify the police who return to the island and arrest the gang. Jimmy then introduces Nadine to his father and is thrilled to learn that Lucy has married a nobleman, thus freeing Jimmy to marry Nadine.
Jimmy Gordon is the son of the bead of the Gordon Syndicate. which owns an island off the coast of Lower California with an opal mine. Gordon Senior is worried about the mine, as the shipments have fallen off, and he is looking for a responsible two-fisted man to send on an investigation. The last Person in the world who answers this description is his son Jimmy. However, the old man receives a shock when one of his employees, Bennie Zussbaum, tells how Jimmy rescued him from a gang of toughs in a roadside café. Old Gordon begins to think well of his son, for the first time. Jimmy is engaged to Lucy Andrews, but it would be quite possible for one to live without the other. Lucy's mother is far more interested in Sir Beverly Wyndham. When Jimmy breaks an engagement with Lucy and she then sees him fighting at the roadhouse, as she drives by in her car, she determines to break with him. His father sends him to Calabas Island. Jimmy says goodbye so hurriedly to Lucy that she has no time to break with him. At the island, Jasper Sneedham, with the assistance of McCool and his native servant, Juan, has been cheating the company. The only honest person is the foreman, Haimer. Jasper has a step-daughter, Nadine. When Jimmy arrives on the mainland, he is met by Juan, and taken by launch to the island. On the way, Juan hits him over the head with a belaying pin. Jimmy manages to swim to the island, and crawls onto the shore. Nadine is playing on the beach. She sees him and calls the foreman to go with her to his assistance. They take the half-drowned youth to Haimer's hut. Jasper comes in haste but is reassured when he finds only a boy, though he recognizes him as Gordon's only son. He offers to show Jimmy over the mine as soon as he is well enough. But Jimmy is far more interested in Nadine than in opals. Jasper makes up his mind that as he has stolen a comfortable fortune, he may as well leave the island before Gordon sends a boat for his son. With McCool and Juan he lays his plans, which Nadine overhears. Jasper has told the girl that she is to marry McCool as soon as they reach the mainland. Nadine goes with her information to Haimer, and they resolve to tell Jimmy of the flight. The launch is ready and Jimmy says that they will beat the other to it. Before he goes, he has just time to give Juan the licking of his life. Jasper has locked Nadine in the closet in her room, and Jimmy hears her call and takes the door off its hinges. Jasper and McCool return and Jimmy holds them up with an unloaded revolver. Armed with an axe, he rushes for the launch with Haimer and Nadine. The others follow, and he fights them with the axe. One of Jasper's men engages Haimer, while McCool, who has sneaked off, catches up Nadine, and attacks her on the cliff. He has no time to run down, so he makes a terrific dive into the sea, and swims rapidly to the beach, rescues Nadine, and knocks McCool out. Then he jumps for the launch, and makes off. Reaching the mainland, they call for the police, who return with Haimer to the island to arrest the gang. Jimmy buys new clothes for himself and Nadine and takes her to his father's office. She waits outside while he makes his report to his father. The old man is delighted, but says that he has bad news for Jimmy. Lucy has eloped with Wyndham. Jimmy is tickled to death with the news and brings in his "real girl" Nadine, whom Old Gordon receives with affection.
