You're an ordinary German, living in 1920's Weimar when the Nazi party takes over - WHAT do you do? That's exactly the question that Katya Hoyer, "Britain's favourite German historian," wanted an answer to.

For her latest book, Weimar: Life on the Edge of Catastrophe, she spent years combing the Weimar archives, inspecting the fates of its citizens who were living through some of the most turbulent times in world history - what choices did they end up making? Did they resist, look away or even support Hitler's murderous regime?

In this gripping conversation, Katja and I talk about Weimar's contrast to Berlin, Hitler's infatuation with the city... But also how it went from being the birthplace of Bauhaus to hosting the biggest concentration camp on German soil...