To generations Arthur Ransome's books, including Swallows and Amazons, were an integral part of growing up. But was there a darker side to the author? In this drama-documentary, the enthusiastic Griff Rhys Jones follows a trail that begins in Russia, reveals close links with many leading Bolsheviks, an affair with Trotsky's secretary and previously unreleased KGB documents about Ransome. But was Ransome actually spying for the British secret service all along?