Reactions to an author taking a detour away from a much loved series, or style (or both for that matter) can vary. Some readers love the chance to head into new territory, others find that departure too much of a step, and long to return to the familiarity of the series, the known characters or the styling. And as with everything, for this reader, it all depends.
OPERATION NAPOLEON is a thriller, set in Iceland, but based around the mystery of a plane that went down at the very end of World War II. To take this that little bit further again from the Erlendur Sveinsson Crime Fiction series, this book also has a central female character. Kristin is pulled into a dangerous world of secrecy and power games when all she is trying to do is discover the truth behind her brother's fate - there on that remote glacier.
I suspect that whether or not a departure from the known works is often to do with the quality of the storytelling. OPERATION NAPOLEON is, undoubtedly, a thriller. There are lots of nefarious goings on, there's danger and conflict, there's the unknown of what was in that plane, why there is so much desire to find it, and claim what it is carrying. So whilst there are many of the elements that a thriller requires, and the pace and plot that supports the discovery of those elements, there are some quintessentially "Indridason" elements to the story. There are some wonderful characters that the reader can identify and sympathise with - it always helps to have somebody to be "barracking for".
There is also the way that this author always manages to weave the landscape and the culture of Iceland into his books, and the way that he uses family relationships as a basis for characterisation and exploration. In this case we have Kirstin and her brother, and the two brothers whose farm sits at the base of the glacier. The relationship between both sets of siblings is interesting - perhaps more tantalising in the case of the farmers, but undoubtedly the motivation for Kirstin's involvement.
There is a bit of a twist in the tail of this story though, and fans of alternative history may find the final proposition a little difficult to swallow or even maybe a little confronting. Given that the book declares itself pretty well as a thriller, this reader found OPERATION NAPOLEON less problematic than other stories of the same nature, having said that, alternative histories do make me twitch.
The good thing about OPERATION NAPOLEON is that it has the basic structure, and many of the required elements of a thriller, but with sufficient characterisation, and a great sense of place and culture that would make the book appeal to readers less fond of the pure thriller format, provided that aspect of rewriting history isn't too firmly in your pet hates listing.