The deaths of two German Socialist exiles from Nazism, Dora Fabian and Mathilde Wurm, in London in 1935, in far from straightforward circumstances, were a cause célèbre of their day. They were of particular concern to the German exile community in Britain and elsewhere, and to the British intellectual Left, who feared not only that National Socialist agents might have been involved but also that the British authorities were intent on blocking the case's thorough investigation. Setting the Fabian-Wurm affair in its context, this study traces the lives and careers of the two dead women and also examines the position of the earliest political exiles from Germany. Drawing on a wide range of archival material, including British official documents never previously consulted, it reconstructs the events surrounding the Fabian-Wurm deaths as well as the repercussions of the affair on other exiles, on British public opinion, British policy towards the refugees and Anglo-German relations.