Charlie Cooper has always loved the stories of King Arthur, especially the ones about his buried treasures. He digs out his metal detector, says goodbye to his family and embarks on an Arthurian investigation.

He travels to Wales, the land of dragons and song, on a mission to discover if King Arthur was a real man or just a myth and if there's any truth behind this treasure story. In the process, he meets treasure hunters of different sorts, a recorder of rare and ancient folk songs, and finds what he refers to as 'his tribe', a metal-detecting club from South Wales.

He's optimistic he will return home a rich man - if not in wealth, then certainly in knowledge.

Charlie Cooper's odyssey takes him to Wiltshire, home to ancient sites such as Stonehenge, Avebury and the Westbury chalk horse. He wants to get to the bottom of why humans feel the need to leave marks on the landscape.

He soon turns his investigation towards a far more recent phenomenon, crop circles, hoping to settle a debate that has plagued his family for years. They believe that crop circles are the work of aliens, but Charlie strongly doubts that. He meets with farmers and secretive 'croppies' (humans who create crop circles), trying to find out how these vast and intricate shapes appear overnight.

Helped by his friend Scott, Charlie takes his research one step further and attempts to shed light on the phenomenon by making his very own crop circle. The humorous trip aboard an old AA van shows him that you only need to scratch the surface anywhere in this land to discover that folklore, myth and legend are very much alive and exert a beguiling power.

Charlie Cooper, who wrote and starred in the BBC's This Country, has a fascination for the weird and wonderful world of British folklore. In this episode, with the help of an old AA van, he goes in search of Black Shuck, the demon dog of East Anglia. Despite a local legend that seeing Shuck brings with it a curse, Charlie meets locals who claim they have survived such encounters. Keen to capture the beast on camera, he attempts an overnight stakeout, with unexpected consequences.

Alleged sightings of this 900-year-old hell hound are recorded almost monthly, so is Charlie in with a chance? His humorous odyssey takes him across Norfolk and Suffolk, where he meets witnesses and learns that in Britain almost every county has its own mythical creature. You only need to scratch the surface anywhere in this land to discover that folklore, myth and legend are very much alive.