The bloody mutiny was a success and Long John is now in command of the Neptune. Following their native guide, the survivors find the mouth of the Amazon and sail on towards Guiana-Capac. But after the dangers of the open ocean, it's the unknown terrors of the jungle they must now face - with a damaged ship and a reduced crew. To what doom will the lush labyrinth of the Amazon lead Long John, Lady Vivian and Dr. Livesey?