Conflict between the forces of light and dark has long been the stuff of storytelling, but seldom is the hero a work of architecture. In effect this is what Simon Mawer has done in his engrossing new novel, where the eponymous room glows like a beacon of love, hope and beauty across six decades of monstrosity. Der Glasraum is the central feature of an extraordinary modernist house, designed for the Landauers, a wealthy couple in the fictionalised city of Město, Czechoslovakia, at the end of the 1920s. Even as Viktor, owner of the Landauer car manufacturing company, and his wife Liesel move into their new home, the threat of Nazism is growing. Viktor is a Jew, Liesel is not. They turn their house, and the glass room in particular, into a haven of culture, civilisation and modernity. But in 1938, as Germany annexes Czechoslovakia, the Landauers flee to Switzerland. By now they have two children, and a governess, Katalin – a Jewish refugee from Nazi-occupied Austria – who is also Viktor’s lover. They cannot know it at the time, but none of them will ever live in the house again.