At first glance the story of an obscure sex scandal among an evangelical sect in 19th-century Prussia might seem a bit slight. But Christopher Clark, one of our greatest historians, uses it as the hook for a haunting reflection on the power of gossip, fake news and social conformity. Sketching the world of Königsberg with tremendous empathy, he gives us an unforgettable range of characters, from the androgynous preacher Johann Ebel to the splendidly named Count Finck von Finckenstein