Five prisoners of war steal a hot air balloon and escape capture in Virginia during the American Civil War. They fly for several thousand miles before a storm forces them to crash land on an unknown island in the Pacific. There, the marooned men must work together to pool all their knowledge and skill if they wish to survive.

But the island has its secrets, and the castaways discover it's not as deserted as they thought. A mysterious figure has been watching them. Does it bring salvation or even more danger?