Within the central group of Ngogo chimps, alpha male Jackson faces possible threats to his leadership and mother-of-two Christine educates her new baby.

While some chimps form new bonds, others plot rebellion. Years of bad blood threaten to erupt into violence when a Western raiding party ventures out.

Jackson's injuries leave him vulnerable to enemies and supposed allies alike as a rainstorm sweeps through Ngogo. Will his rule as an alpha end here?

In search of fruit, rival chimps from Western Ngogo venture into disputed territory and seize an opportunity to send others nearby a warning.