All aboard! Join Molly on a brand-new adventure as she and Trini take a train from Denali to Anchorage, Alaska. But this is no ordinary train – it’s the MYSTERY TRAIN! When a jewel necklace goes missing, it’s up to Detective Mabray and her assistant Dr. Mumford to solve the case! Follow along as Molly and Trini search for clues with some unexpected guests, decipher some strange bird calls, and even get stuck in a spooky town, all while riding the mystery train!