Young chimp Ben's mysterious bacterial infection causes him to lose a toe, while another primate in Hananya's house is struck down by the same illness. Capuchin TJ settles in well with the ladies and his South American housemates learn how to forage for food. Members of staff hide hard-boiled eggs for the capuchins to find and animal director Jeremy has a run-in with female orangutan Lingga.

Alison Cronin visits Dao Tien island in Vietnam, the site of Monkey World's foreign sanctuary for endangered primates. Meanwhile, the team learns that two rare monkeys are being kept in a theme park outside Ho Chi Minh City, and tries to get them freed.