After months of secret toil by day and by night, Gar El Hama perfects a means by which to escape from prison. He succeeds at last in removing a slab from the floor of his cell and drops through a shaft to the engine room below. There he overpowers the engineer, dons the latter's clothing and is passed by the guard at the door on the pretense of going for oil. Free again, he sets out for a new adventure. Disguising himself, he attends a reception given by Consul Johanna. Meeting the Consul's daughter, he decides to abduct her and demand ransom. During the reception he examines her apartments, unlocking a window, and returns in the night, entering through this window with his assistants, and takes her aboard the schooner owned by him and his pirate gang. He then sends an unsigned letter to the Consul, stating that his daughter, Katherine, will be held until a ransom of $25,000 is placed at the foot of Victoria Monument, naming a time when it should be placed there. Katherine's fiancé, Lieutenant Erskin, sets out to find her. He is told by pilots that a girl was taken aboard a mysterious schooner the night before, so he charters a tug and goes in pursuit of the schooner. Gar El Hama and his gang arrive at Snake Island and take Katherine to their headquarters there. She escapes from the headquarters but is recaptured on the island and taken on board Gar El Hama's private yacht. Lieutenant Erskin and his friends arrive at the island, attacking the pirate gang. Gar El Hama escapes through an underground passage and Erskin, as he gropes his way through the dark tunnel in search of Gar El Hama, is captured by the latter and taken to the yacht also, and is bound and locked in a stateroom. He finds a lighted lamp with which he burns the ropes, and forcing the door, sets himself free. The pirates neglected to take his revolver, so he goes down to the engine room, locks the engineers in a closet at the point of his revolver and overpowers the fireman. He pours water on the fire and removes parts of the engines, disabling them, which brings the yacht to a standstill. He does this, knowing that his friends are in pursuit, in order that they may overtake the yacht. He steals up behind Gar El Hama, overpowers him, and then finds Katherine in the cabin. He seeks to defend her and himself from the pirates, but when Gar El Hama recovers, he and his men recapture and make prisoners of them both. Soon, however, Erskin's friends arrive, attacking and capturing Gar El Hama and the pirates, rescuing Erskin and his fiancée. The yacht is towed back by the tug, Katherine is restored to her home, and Gar El Hama is thrown into prison again.