Disaster strikes at the orang-utan nursery when builders try to fit the new windows, baby woolly monkey Diego meets one of his family for the first time, and Samantha the squirrel monkey gets the all-clear from the park's vet.

Alison Cronin visits Dao Tien, Monkey World's sister centre in Vietnam, which was founded in 2008, and has since become the site of a pioneering rescue and rehabilitation mission for golden-cheeked gibbons. Here, the team faces trouble during an attempt to save a rare silver langur monkey, and director Marina asks human doctors to perform ground-breaking eye surgery on a gibbon.