Millionaire Hoarders returns, as experts sift through houses, stately homes and castles crammed full of potential treasure to unearth items that could raise life-changing sums of cash. But can our fanatical collectors bear to part with their beloved possessions? In this episode, Claire and Frankie - the current custodians of the national landmark Bamburgh Castle, in Northumberland - are constantly thinking of ways to entice visitors through their doors, and a plan to create a brand-new visitor attraction is on the cards to help drive tourists. However, with the mounting costs required to maintain this stunning castle for the nation, they are in dire need of a cash injection, so they call on expert Clive to help look for something among the castle's archives. Clive is stunned when he discovers a wrecked Mark1 Spitfire within the castle. Meanwhile, vintage-loving Bola collects all things retro, including cars, clothes and china - but now her son needs funds for his chosen career. Can expert Paula help?