S6, EP15: Bertie's Historic Discovery (Audio Story)

In the penultimate episode of 'Series 6', a visiting bus named Algy comes to the island during the summertime and claims that Bertie has never done anything exciting within his time on Sodor.
However, when Bertie feels put down by Algy's remarks, he accidentally finds himself on an unexpected route which then leads him to a long, lost piece of history belonging to the Hatt Family...
Any generation of 'Thomas & Friends' fan can enjoy this video.