It's a very special day for Grandad Tumble. He's getting a lifetime achievement award for all of his hard work over the years driving buses. Aunt Polly and Baker Tumble are planning to make a huge chocolate cake, and Mr Tumble will be there to help celebrate too. Unfortunately, when Mr Tumble arrives at the bus museum, he's mistaken for the new cleaner and is set to work by the manager. He tries his very best, but accidents will happen! There's a lot of mess, a tour group to manage, an escaped dog and a sing-song or two! Justin Fletcher stars, alongside Nina Wadia and George Webster