Five prisoners escape by balloon from a siege during the American Civil War. The castaways land on a remote spot, which they name 'Mysterious Island'. Gideon, the journalist; Herbert, a young boy; Neb, a black man; Captain Harding, of the Northern Army; Captain Jack a sailor and Top, their dog, find Ayrton, the lone, demented castaway. He regains his senses during a struggle as the group is attacked by pirates. They attempt to escape by building a boat. The remarkable story concludes with their discovery by Captain Nemo and the crew of 'The Nautilus'.