From a Scottish Castle to a Merseyside boozer, this is the story of a missing masterpiece. Olivia Graham investigates the biggest single artwork theft in British history and discovers how her family became caught up in the hunt for a stolen da Vinci.

James Peak isn't an art critic, or even a journalist. He's a Banksy super-fan, and in this series he, and his soundman Duncan, get closer than close to Banksy's secret world, telling the story of the graffiti kid who made spraying walls into high art, the household name who is completely anonymous, the cultural phenomenon who bites the hand that feeds him. James persuades a member of Banksy's secret team – someone who worked closely with the artist when they were starting to cut through – to talk about the experience. The story that results is a rollercoaster ride... In the last episode of this series, Banksy springs a surprise retrospective show in Glasgow, and we hear why Steph told her story. Written, Produced and Presented by James Peak Sound & Commentary: Duncan Crowe. Voices: Keith Wickham & Harriet Carmichael Music: Alcatraz Swim Team & Lilium Series Mixing: Neil Churchill Executive Producer: Philip Abrams With special thanks to Hadrian Briggs, Pete Chinn, Patrick Nguyen, John Higgs and Steph Warren. An Essential Radio production for BBC Radio 4

James Peak isn't an art critic, or even a journalist. He's a Banksy super-fan, and in this series he, and his soundman Duncan, get closer than close to Banksy's secret world - telling the story of the graffiti kid who made spraying walls into high art, the household name who is completely anonymous, the cultural phenomenon who bites the hand that feeds him. James persuades a member of Banksy's secret team – someone who worked closely with the artist when they were starting to cut through – to talk about the experience. The story that results is a rollercoaster ride. In this episode, help arrives for Steph from an unlikely source - a person we've heard quite a lot from already. And we head off to Weston-super-mare for a very special Banksy show. Written, Produced and Presented by James Peak Sound & Commentary: Duncan Crowe. Voices: Keith Wickham & Harriet Carmichael Music: Alcatraz Swim Team & Lilium Series Mixing: Neil Churchill Executive Producer: Philip Abrams With special thanks to Farhath Siddiqui, Bryn Youlds, Hadrian Briggs, Pete Chinn, Patrick Nguyen, John Higgs and Steph Warren. An Essential Radio production for BBC Radio 4

James Peak isn't an art critic, or even a journalist. He's a Banksy super-fan, and in this series he, and his soundman Duncan, get closer than close to Banksy's secret world - telling the story of the graffiti kid who made spraying walls into high art, the household name who is completely anonymous, the cultural phenomenon who bites the hand that feeds him. James persuades a member of Banksy's secret team – someone who worked closely with the artist when they were starting to cut through – to talk about the experience. The story that results is a rollercoaster ride. In this episode, Banksy returns to Bristol Museum in triumph, while Steph is accused of forgery. Written, Produced and Presented by James Peak Sound & Commentary: Duncan Crowe. Voices: Keith Wickham & Harriet Carmichael Music: Alcatraz Swim Team & Lilium Series Mixing: Neil Churchill Executive Producer: Philip Abrams With special thanks to Hadrian Briggs, Pete Chinn, Patrick Nguyen, John Higgs and Steph Warren. An Essential Radio production for BBC Radio 4

James Peak isn't an art critic, or even a journalist. He's a Banksy super-fan, and in this series he, and his soundman Duncan, get closer than close to Banksy's secret world - telling the story of the graffiti kid who made spraying walls into high art, the household name who is completely anonymous, the cultural phenomenon who bites the hand that feeds him. James persuades a member of Banksy's secret team – someone who worked closely with the artist when they were starting to cut through – to talk about the experience. The story that results is a rollercoaster ride. In this episode, a nightmare exhibition on Oxford Street sees Steph in big trouble with the big man. Written, Produced and Presented by James Peak Sound & Commentary: Duncan Crowe. Voices: Keith Wickham & Harriet Carmichael Music: Alcatraz Swim Team & Lilium Series Mixing: Neil Churchill Executive Producer: Philip Abrams With special thanks to Hadrian Briggs, Pete Chinn, Patrick Nguyen, John Higgs and Steph Warren. An Essential Radio production for BBC Radio 4