Cara is very sad when she breaks her leg and isn’t able to join her best friends on their summer activity holiday. To cheer her up, Mum takes her to Battersea Dogs & Cats Home, where they meet Stella the gorgeous and gentle Staffordshire bull terrier puppy. Stella goes everywhere with Cara — even on the bus to a birthday party! But one day an overexcited Stella bounds onto a bus and the doors close before Cara can join her, carrying her away. Will Cara ever be reunited with her runaway puppy?