A mad genius tries to bomb the world into peace.

In the 19th century, government agent Strock is ordered to sail in a balloon over a Pennsylvania crater to investigate a series of mysterious eruptions. Accompanying him are a munitions maker, Prudent, with his daughter, Dorothy, and her fiancé, Philip. Their balloon is shot down over the crater, and they become the prisoners of Robur, an inventor who has built a fantastic flying ship, Albatross , which he plans to use to destroy all instruments of war, thereby bringing lasting peace to the world. With his prisoners aboard, Robur proceeds on his mission across the world, bombing London, the English navy yards, and the armies of Austria and Egypt. Realizing that Robur is mad, Strock determines to destroy Albatross , at the risk of death to all aboard. When the flying ship lands for repairs at a Mediterranean island, the prisoners escape, and with ammunition taken from the ship's armory, Strock sets off an explosion that sends Albatross , Robur, and the crew to the bottom of the sea.