The basic premiss of this book was about a modern international fleet of naval warships 2021 is caught up in an experiment which lands them bang, in the middle of the Battle of Midway during World War 2.
It is a genre of historical, science and alternate fiction. This first novel Birmingham doesn't go down the 'what if', my grandmother was killed scenario, that most time travel fiction tries to get there head around.
Rather Birmingham looks at comparison, between weapons of different eras, culture between different nationalities but different times. For example in the 1940's equality between sexes, cultures and colors was still racist.
The most important aspect in this book which quickly becomes apparent is not the technological advances but the knowledge of history in the short term. How both the Axis and Allies can take advantage of the historical knowledge for there Global strategic advantage. This is very apparent in the last few pages (Which I wont give away), and has me eager to read the next book in the series.