Antiques experts travel across the country, competing to make a profit at auction. Catherine Southon and Philip Serrell battle it out for the last time. Travelling through south Wales, the old Citroen DS20 takes them to the final auction in Wells, Somerset. Catherine heads to the Royal Mint and finds out how Sir Isaac Newton revolutionised coins to prevent forgers making a fortune. Phil breaks from shopping for a little lesson in culture at the Bristol Old Vic and discovers why it is a miracle the building still stands today. At the final auction it is the battle of the watches. Phil and Catherine each buy fascinating timekeepers, but which one will make the most profit?