S13·E12 Episode 12

Catherine Southon and Philip Serrell continue their antiques adventure in a classic Citroen. In Winchester, Catherine finds a jolly nice croquet set and, in Alton, she finds a rare 1930s novelty biscuit tin, both of which give her a chance of huge profits at auction in Christchurch.

Meanwhile, Phil learns how flying boats gave us the word airport. Catherine unravels the story of a top-secret unit of World War II spies working in occupied Europe and the crack team of code deciphers back here in Blighty tasked with keeping their undercover colleagues alive.