Tensions are high as Sammy the chimp, one of the park's oldest and most popular residents, goes into surgery. The stump-tailed macaque house gets a makeover to accommodate its elderly monkeys and the capuchins go cherry-picking.

Alison collects 10 stump-tailed macaques being retired from a research facility in Edinburgh. The journey is potentially dangerous as the stumpies have never been outside before and some of them are old and frail. Back at the park, staff are anxious as chimp Athena undergoes an eye operation, while squirrel monkey Fidget is a hit with the ladies.