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.

Carmarthenshire County Museum is a slice of history in itself. The building that houses it has been in continuous use since the 13th century, once a Bishop's palace it was where the Bible was first translated into Welsh. But could it also be home to some mysterious cases of mistaken identity and two lost paintings from the time of Charles II?

Dr Bendor Grosvenor and Emma Dabiri travel to Carmarthenshire to investigate two intriguing portraits of a local nobleman and his wife, the Earl and Countess of Carbery, possibly painted by the great Sir Peter Lely in the 17th century.

Yet all is not as it seems: Bendor has a hunch that one of the portraits is by another hand. Could the portrait of the Countess be a lost work by Mary Beale, Britain's first commercially successful female artist?

While Bendor gets to grips with the badly damaged portrait of the Earl, Emma traces the story of how he survived the Civil War, how Mary Beale was written out of the history books, and discovers how the cross-dressing men of the Rebecca Riots stormed Carmarthen.