I ended up DNF the first book in the series as it wasn't to my taste and so I was unable to review this series in full. I thought it was a tad too young for the audience it was pitched and it really didn't hold my attention. I read a lot of books in this genre and this series really didn't hold my interest long enough for me to invest in the number of books this series covers

I usually enjoy Gregory's novels, but I could not get on at all with thus book. Before reading this instalment in the Luca and Isolde series, I brought myself up to date with the main plot. Two lonely young people meet under unusual circumstances and remain in each other's company for while. Luca, a monk of the Dark Order, has been sent to investigate dark phenomena that may herald the end of days. Isolde is on the way to her godfather to raise an army against her brother who stole her inheritance. Together they end up in many difficult situations, and a forbidden and mostly platonic love develops.
In this book they find themselves in Austria, trying to solve the mystery of the dancing illness. This leads to a series of mishaps and adventures, which lead them to consider humanity's nature and the question of whether human beings are inherently good or evil.
Clearly inspired by the holocaust and antisemitism, this book is published very timely for the Holocaust memorial day. However, irrespective of its good intentions, the book fails to inspire, mostly because of the stilted and insipid characters that dominate the story. While the concept is an interesting one, the language the novel is written in falls far below the usual Gregory eloquence, which also takes away from the plot.
Overall, it is probably an entertaining enough read. But if you are looking for something slightly more intellectually demanding, you will have to turn to her previous works.