A fascinating take on an intriguing set of events and little told pre-war period in Germany. The author's connection to the real life Ruth Blatt makes it all the more interessant. Funder has in some cases only the barest facts to go on and mostly does remarkably well to string a narrative together. Best example is probably that there's only the briefest of references (secondary source I think) to an affair between Ernst Toller and Ruth Fabian, yet this love is one of the drivers of the novel. One forgives this fiction of important lives and events because Funder gets the story out there, again. It's an honouring of those in the resistance that shouldn't be forgotten. Some devices didn't always work, though, and the relationship between Ruth and Hans was problematically handled, it sometimes seemed difficult to believe.
The structure used, telling the story from two people's perspectives, actually worked well for me. In other works I cannot stand this approach, but it worked in this case, because (I believe) it was essentially what two not intimate people (Ruth and Ernst) experienced of a common friend (Dora) with whom both were very intimate. That 'twin view' of Dora I found comfortable, even pleasant, as that's how real life is - multiple views of the same person or event, adding up to a kaleidoscope of opinion and experience.
Overall I found this a very compelling book that sheds light on something I knew virtually nothing about. I found it hard to put down and finished the second half in a single sitting - driven along by the story.