Danger Island

Mu-tan and his pirates board Dr. Hayden's boat and take him and Leslie captive. Upon surfacing, Link goes to their rescue, only to be thrown overboard. After taking the treasure, Mu-tan blows up their boat.

Link is attacked by a shark while swimming to the nearest beach, but manages to frighten him away. He reaches the beach, where a leopard finds him and a fight ensues; luckily, he is not harmed. The leopard retreats and Link collapses on the sand.

After collapsing on the beach, Link is found by Morgan. Out at sea, Dr. Hayden tells Mu-tan where the lost city of Tobanya is, but only after Leslie is threatened by him. Mu-tan tells them they will be going with him and his men, and if they do not find the lost city, they will be killed.

Morgan and Chongo find Link Simmons on the beach, where he had collapsed. At first, Link is afraid of them, but Morgan tells him that they were merchant marines who were thrown overboard and they, too, were washed ashore. They take Link to their cave and explain that the natives of the island are headhunters.

Morgan and Chongo show Link the traps set all over the island by the headhunters. In their travels, they come across these traps and Link is saved by Morgan many times. Chongo sees smoke in the distance and, aware that the headhunters are close by, they start to run back to their cave, only to find themselves surrounded by the headhunters.

Surrounded by headhunters, they (Link, Morgan and Chongo) must fight the natives. They manage to escape with the natives in pursuit. After a few harrowing experiences, they outwit the natives and return to the safety of their cave. Meanwhile, Mu-tan and his men reach the shore with Dr. Hayden and Leslie as their prisoners.

Upon reaching the shore of the island where Dr. Hayden had told them they would find the lost city of Tobanya, Mu-tan threatens Dr. Hayden with his life if the lost city is not found. Mu-tan does not believe the doctor is telling the truth and he and Chu fight over who is captain.

Upon returning to their cave, Morgan, Chongo and Link are attacked by some natives who were waiting for them to return. After a good fight, they rid themselves of the natives. Meanwhile, back at the shore, Mu-tan has tied Dr. Hayden and Leslie so they cannot escape.

Chongo has discovered a ship anchored off the island. He, Morgan and Link run to the beach where they find Mu-tan and his pirates. They scare them off and rescue Dr. Hayden and Leslie. Morgan tells Dr. Hayden he had found a boat off an inland island along with some maps and other articles. Dr. Hayden feels that these articles and maps belong to his brother, Philip, who was lost near the islands some years before. They decide to go back to the cave and take a look at the map so they can start their search right away.

Dr. Hayden and his daughter, Leslie, begin their journey to the cave with Morgan, Chongo and Link. After a dangerous trip, they return to the cave.