Despite its cumbersome title, this latest Thomas the Tank Engine special sees a significant expansion in ambition for the amiable set of chuffers: with Eddie Redmayne and John Hurt on board, as well as Olivia Colman back for another go as neurotic steam-shovel Marion, we are firmly in the realm of celebrity casting. Not that it makes much difference to the actual content of the film, which remains reliably well-pitched at little ’uns and their slightly older siblings. Like Tale of the Brave, Lost Treasure jams locomotive action together with a pop motif supposedly beloved of kids: Brave had dinosaurs, Treasure has pirates. In short, a sinister-looking sailor is riding Sodor’s rails looking for a missing chest of loot. Shenanigans ensue. Not an all-time classic, but an efficient diversion for the start of the summer holidays.