Modern biography. Rather disjointed, and persistently uses German titles of books without even having a simple list to cross-check them. Some areas too brief (Dora squeezed on to a few pages at the end) and the chronology occasionally jumps a little. On the other hand, the lit crit is better, so overall, probably 2.5 stars.
See my Kafka-related bookshelf for other works by and about Kafka (http://www.goodreads.com/review/list/1199525-cecily?format=html&order=a&shelf=kafka).