At Animal Ark, Mandy Hope helps her parents treat animals of all shapes and sizes. Even outside the clinic, Mandy can't resist helping any animal in need. When James leads Mandy to a badger nest he's been watching, they find that it has been deliberately destroyed. All that is left is an orphaned badger cub. Can they discover who did this cruel thing and will they be able to find a new home for the cub?

The Hope household gains two new temporary members--young Polly, whose father is in the hospital, and her Shetland pony, Shona--giving Mandy Hope, an animal lover who helps her parents at their veterinary clinic, a new challenge: helping Polly overcome her fear of horses and finally learn to love her own pet.

Mandy and her friend James, assisted by Blackie the labrador retriever, help Mandy's grandmother save the village hospital from being closed and, at the same time, save the lives of a newborn lamb and their young neighbor, Jenny.