Interregnum offers an alternative history of the country's--and Winston Churchill's--finest hour. 1946. Britain is occupied by Nazi Germany. All seems lost--until the February Rising sees off Hitler. The Fuhrer's death triggers a struggle for power among the Nazis, revolt across the Occupied Continent, and schism in the Oval Office in Washington. Caught in this maelstrom are the teenage princesses Elizabeth and Margaret. For Churchill,...