The fantastic Captain Nemo once again inspires the spirit of adventure in another Jules Verne classic. Captain Cyrus Harding (Michael Craig) leads three Union soldiers in a daring escape from a Confederate prison camp in a seized Confederate balloon. The group becomes marooned on an island, where the mysterious Captain Nemo (Herbert Lom) comes to their aid. But when a volcano erupts and threatens to destroy them all, can Nemo save the day?