I started off rather enjoying this, but it frankly became a something of a slog. The setting is a present-day Britain where, within the government, there exists a shadowy organisation known as the Checquy. It has existed for many centuries and is made up of 'talented' individuals, usually recruited as infants and raised to serve and protect the British Isles. Think X-Men meets Charles Stross' Laundry Files meets Harry Potter. 
 We start with Myfanwy Thomas coming to with no memory, surrounded by bodies, in a London park. At least, the letter in her pocket tells her that's who she is - or, rather, that is the identity of the body she inhabits. This missive and the trail of information she follows are written by the 'real' Thomas, a highly placed administrator at the organisation, who has received several telling prophecies that she is to die and her body is to be re-inhabited by another. What's more, it is another member of the Checquy ruling elite who is responsible. 
 This is an intriguing idea, a nice fantastical twist on the venerable DOA motif; the crime has already been committed, and the first person narrator is trying to find the perpetrator. And it starts well enough, building the new Myfanwy's character, with all it's unmoored uncertainty as she struggles to fit into this life at the same time as investigating the ongoing crime - because, of course, her predecessor's obliteration is part of a grander scheme. 
 This was one of the first sour notes. Once she begins to interact with the other members of the organisation, with all their strange powers and arcane knowledge, people barely bat an eye at her sudden change of character. These are people who know there are individuals and organisations with powers exotic and powerful and multifarious, but don't consider that this highly-placed officer might have been replaced by an imposter? However, I reinforced my willing suspension of disbelief and rejoined the ride. 
 Unfortunately, my perseverance wasn't rewarded. While there are many excellent ideas embedded within the story, it needed more thought and, quite honestly, a good deal more editing. Increasingly problematic are the notes left by the original Rook Thomas for the replacement; the original purpose of these is to guide her substitute with the information she has managed to glean prior to her own 'murder'. As this seems to be building toward something the reader can't help but think "why not just skip ahead and find out what's going on?" but then the author begins to pad these epistles out with stories of Thomas background which, while arguably interesting backstory, are entirely inappropriate and act as massive info dumps, a terrible example of the writer feeling the need to show their working. 
 I confess that I started skim reading, also encouraged by a tonal monotony and the fact that the writing just wasn't executed well enough to carry the whole thing off. When a big action scene and reveal left me yawning I knew I wasn't going to continue with the series. There's definitely potential here, but the whole needed tightening up.