Brother and sister, Harry and Abi, fight like cats and dogs. They can't agree on anything! Harry really wants a dog as the new family pet, but Abi is desperate for a kitten. A visit to Battersea Dogs & Cats Home provides a surprising end to their argument. Jazz the black kitten and Bo the Boxer puppy were raised together and can't bear to be parted - and so both Abi and Harry's Christmas wish comes true when BOTH animals come to live with them! Everything seems perfect - but things go horribly wrong when Abi irresponsibly sneaks Jazz to their school carol concert. Jazz goes missing - but will Bo be able to find her?