Eighty-eight capuchin monkeys rescued from a research laboratory in Chile wake up to their first morning at the Monkey World Ape Rescue Centre in Dorset. Young chimp Rodders has trouble with a sticky melon, and the park's naughtiest resident, Seamus, comes face to face with alpha male Butch.
Wildlife vet John Lewis is given a run for his money as he tries to sedate two excitable chimps. The recently rescued male capuchins get used to life together, and orang-utan Kai proves too energetic for her companions.
The team is forced to step in when Ben is injured by the alpha male during the chimp introduction. Orang-utan Hsiao-Quai struggles with her ever-growing son Kai, and staff at Monkey World prepare to welcome a new arrival.
Alpha male Hananya shows his dislike for needles, while the other chimps have a banana-fishing expedition. Alison and Jeremy Keeling rehouse two capuchin monkeys in Hertfordshire, and there is an exciting development among the endangered gibbons.
Resident capuchin TJ causes mischief when he joins the new Chilean arrivals, and alpha male Paddy has to step in. Orang-utan Amy is pregnant but the keepers worry she will not be able to care for a baby, and chimps from Hananya's group get their teeth cleaned.
The team must make an important decision concerning the safety of a chimp group when alpha male Hananya continues to exhibit violent behaviour. Elsewhere, chimps Simon and Eveline compete in a swing-off, dental surgery is carried out and the park's staff prepare for the next woolly monkey birth.
A baby chimp tries to prove he is grown up enough to go it alone. The Bachelor Boys' reputation takes a knock when they become frightened of a new toy. Two of Hananya's charges pluck up the courage to explore their surroundings, and the Chilean capuchins get their first taste of life in the outside world.
The park hosts a morning sing-off, and golden-cheeked gibbon Zoey introduces a new member of the family. Over in Hananya's group, hot potatoes are on the menu, and a fight among the female capuchins leaves Phoebe with a bite wound that requires surgery.
Baby woolly monkey Paulo meets his new family for the first time, while chimpanzee Eddi has fun with his young brother Bart. Pregnant orang-utan Amy gets to grips with a breast pump, and emotions run high when a marmoset arrives at the park.
Mad Max meets his new housemates, and chimps Ben and Pip get a shock when they have another encounter with alpha-male Hananya. Piquita is the centre of attention in the woolly monkey enclosure, while Bart enjoys honey for the first time in Paddy's chimp group.
Pregnant woolly monkey Piquita approaches her due date at Dorset's Monkey World, while capuchin Sean from Chile demonstrates his grooming skills and ruffed lemur Blue's life hangs in the balance.
A baby woolly monkey is tempted into the outside world by the prospect of some tasty bugs. Meanwhile, the capuchins enjoy a feast of onions, and the keepers plan a radical scheme that will allow a third meeting between young chimp Ben and alpha male Hananya.
The female capuchins fight, Tia needs surgery, and orangutan Amy enters the late stages of pregnancy. Elsewhere, there is a new addition to the play area in the chimp nursery, and Alison visits Paulo - the baby woolly monkey she has successfully hand-reared - for the final time.
Animal director Jeremy is concerned about Ben the chimp, who has a nasty foot wound, and there is an update on Paddy and his baby Bart. Gibbon Tien undergoes a transformation and keeper Holly checks up on woolly monkey Xuzy.
An infection threatens to sweep through the chimpanzees, prompting the keepers to begin urgent action to save their lives. Meanwhile, the overweight orang-utans continue with their diet and the lemurs are introduced to the stump-tailed macaques before they move in together.
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.
A pair of Mueller's gibbons develop a taste for life in the treetops, while three endangered golden-cheeked gibbons move into the enclosure next door. Meanwhile, a specialist doctor is called in when Freddy's bowel complaint fails to improve.
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.
A balding macaque receives protection from his troop's over-enthusiastic grooming, and the park is saddened by the death of alpha male capuchin Tom, who was at the centre for seven years. Elsewhere, the chimps are given walnuts and Jestah gets more than his fair share.
Alison Cronin springs into action when an adult female chimpanzee in Mexico urgently needs the team's help. Even Lulu joins in the fun when the nursery chimps have a play session, and Kai tries to act independent and grown up while discouraging Amy from joining in his games.