First things first, the publishers would have you believe that this is on a par with the Shardlake novels by CJ Sansom - well, put simply, it isn't. Having said that, once you put aside the comparisons and read it without prejudice then you will probably enjoy it. The setting in turbulent times, provides plenty of opportunity for period detail and it is clear that Clements has brough to bear all his knowledge as a historian. The result is a kind of medieval Day of the Jackal meets Jack the Ripper via Name of the Rose.
The plot and sense of time and place are excellent, and Clements delights in the gruesome, as Shakespeare pursues his serial killer/assasin, all the time trying to stay one step ahead of his rival, Richard Topville. And therein lies a problem, why create a brother for William Shakespeare, when everything else was so historically accurate? Was it merely to facilitate one unlikely setpiece late in the book, because I could see no real need for it. There are a couple of other out of place elements, which I won't specify as to do so would spoil the atory if you want to read it, but suffice to say that they appear out of place for the 16th Century.
I also felt that the ending of the book left much to be desired - there seemed to be a few false starts, as if the author wanted to bring things to a climax, but the publisher neede more, so he strung things out for 50 or so more pages. The result was several loose ends, obviously to allow for a sequel or two, and a highly manufactured resolution to Shakespeare's domestic arrangements and his love life, the latter, an aspect of his character which never seemed quite convincing.
So if this is the start of a series, it is one which will probably prosper, but the writing needs to be sharper, the plot a little pacier and the characters given more depth.