Summer 1941, Hitler and his allies rule Europe from the Atlantic to the Black Sea. But inside Germany, there is a notable voice of dissent, Der Chef, whose radio broadcasts skilfully question Nazi doctrine. What listeners don't know is that Der Chef is a fiction, a character created by the British propagandist Sefton Delmer. As Peter Pomerantsev uncovers Delmer's fascinating lost story, he is called into a wartime propaganda effort of his own: the global response to Putin's invasion of Ukraine. From one of our leading experts on disinformation, the incredible true story of the complex and largely forgotten WWII propagandist Sefton Delmer - and what we can learn from him today.