Pollok House is a country house right in a Glasgow city park, owned by Glasgow City Council and looked after by the National Trust for Scotland. It has a collection of Spanish art, the legacy of the man who once owned the house, Sir William Stirling-Maxwell. Unfortunately, some of its treasures have been placed in storage due to a leaking roof and renovations. But could one of these displaced pictures be a priceless lost work by Rubens? The painting's subject is George Villiers, Duke of Buckingham, the gay lover of James VI of Scotland. While Bendor squares up to a rival portrait in Florence which claims to be the real Buckingham portrait by Rubens, Emma finds that Stirling-Maxwell had a secret family in Jamaica and that sugar and tobacco built Glasgow long before shipbuilding was its major industry.