Joan Greenwood

When his mother eloped with an Italian opera singer, Louis Mazzini was cut off from her aristocratic family. After the family refuses to let her be buried in the family mausoleum, Louis avenges his mother's death by attempting to murder every family member who stands between himself and the family fortune. But when he finds himself torn between his longtime love and the widow of one of his victims, his plans go awry.

During the US Civil War, Union POWs escape in a balloon and end up stranded on a South Pacific island, inhabited by giant plants and animals. They must use their ingenuity to survive the dangers, and to devise a way to return home. Sequel to '20,000 Leagues Under the Sea' .