The new orangutans are introduced to their rescue center.

Hamlet, an older, larger male from a neighboring island, comes to the island and attempts to kidnap Jasmine, although his attempts are foiled by the bandit boys, Saturnus, and Daisy.

The wet season arrives and Oyoy and Mogok become independent. Mogok successfully survives 6 days alone, but Oyoy dies when he falls into the growing river.

Chen Chen, Cha Cha, and Daisy discover that the electric fence separating Orangutan Island, and neighboring Palas Island is not functioning properly, and two Palas Island males get across. They are rounded up by the Teknisi, but Cha Cha is missing.

All of the orangutans are inspected for the first time by Lone and their vet, Tim. Milo bullies Bonita, and Cha Cha is found all alone in the forest.

Donald catches a mysterious disease that spreads throughout the island.

An invisible menace is threatening Orangutan Island, and at the Nyaru Menteng Clinic veterinarians work around the clock to unravel the mystery behind Donald, Togar, Mercury and Bonita's illness. Back on the island, fears of an epidemic worsen when Bertha is found to have an abscess.

Jordan, the main outsider of the group, becomes more active with Chen Chen and seems to be good at climbing trees. Alibaba finds a jackfruit, and it is shared, but Daisy wants Nadi to share it with her, and doesn't let Nadi onto the platforms. She is bitten by a pit viper.

Nadi is treated for a snakebite. She recovers and is sent back to the island. Alibaba raids the fish traps that the Teknisi set up, and earns a higher place in the group's social status.

Most of the orangutans sleep on the forest floor, but they are vulnerable to predators and it is not safe, so Lone tries to build a platform in the tree canopy, away from the ground, to encourage them to sleep in the trees.

Lone's risky plan to encourage the orphaned orangutans to spend more time in the treetops has a fatal flaw. But she isn't going to be discouraged and works on a new solution. At the same time, the island is simmering with tension over who will fill the leadership void until the unexpected return of Hamlet. But his reappearance doesn't immediately resolve the issue as another showdown begins.

For the anniversary of the island, Lone comes for a visit.