In this fifth book in the series, the author departs once and for all from a path that did once run parallel in a way to the Napoleonic Wars that we know from history, as Napoleon invades England, and the corps is called on to work with the army and the militia to try and force him back across the Channel.
Will Laurence has never been a light-hearted character, always constrained by his notions of etiquette, duty and honour, and now he is completely weighed down by the consequences of his actions at the end of the previous book. I haven't quite worked out why I so enjoyed reading about a character who is often such morose company, but I did.
Again, some of the characters are far from rounded - Laurence's former fiancee and her husband seem to be present solely as a plot device - but these are notable as exceptions rather than the rule. And also on the negative side, I was made a more than a little dizzy by the speed with which various characters sped around the British Isles. But these points were outweighed by far by what I really liked, in particular the characterisation of the dragons, including those found in the breeding ground; the development of the characters of the aviators (looking back to the first book); the characterisations of Wellington, Napoleon and Nelson in particular as men from history interwoven into Novik's fictional world; and finally the plot itself. Yes, there are some weaknesses, but there is also much originality and many clever touches.
I don't know if a further book is planned. There is a more complete ending to this than to the previous books, I think. I would like to read of their further adventures in ... (that would be telling!), but if there is no more to come, then there is enough in the existing books to warrant re-reading, and I can find the elusive Throne of Jade, which I have to read out of sequence as I couldn't get hold of it and was too impatient to wait for it before going on with the rest of the series!