We rejoin Catherine Southon and Phil Serrell as they embark on the fourth leg of their trip. A classic Morgan Roadster carries them onwards through the Home Counties of Buckinghamshire and Hertfordshire as they head towards their penultimate auction. Catherine shells out for not one, but two, vintage chairs, a Murano glass bead necklace, an ebonised elephant head page turner, a police helmet and a cheese mould. Very eclectic! She also pays a visit to the British Film Institute National Archive to find out how our nation's film history is being kept alive for future generations and marvels at clips of a road trip - 1920s style. Phil goes all out to win and splashes serious cash on some Murano of his own, a stylish library chair, horses sculpted in leather, an elegant mirror and a set of antique scales. It's still all to play for, so will Phil's gamble pay off or will Catherine romp home to victory?