One of Francis' later books, this bears all his hallmarks ~ strong, self-sufficient protagonist, link to horse racing, a single but largely hidden enemy, a lot of research in a different field (in this case, politics) ~ but is not as strong or enjoyable a read as some of the earlier of his novels. I think that when following a structure or formula which has become very successful, the temptation for an author to skimp on novelty must become quite strong; i fear that this time Francis was not able to resist it as fully as he did on other occasions. There is little precise one can put a finger on and say, “This is poor” or “this ought to have been done differently”, but there is a general atmosphere of settling rather than driving for the best.
One sequence i feel that is less than sparkling is occurs towards the end of the book as the protagonist, a politician's son, is led to reconstruct an attempt which had been made on his father's life some years earlier; there is simply no reason given (presumably because Francis couldn't, or couldn't be bothered to, think of one) for this reconstruction, but it is necessary for the driving forward of the plot to the final dénouement Poor writing, i fear.
A second example is to be found a little earlier in the action, at 10Downing Street, when the politician father is unable to resist sitting in the Prime Minister's chair; we are already fully aware of his desire to progress, indeed of his ultimate aim of becoming Prime Minister, and that little action is not necessary: It adds nothing to our understanding of the character (except, perhaps, causing a little puzzlement about a man who cannot control his instant gratification desires), nor his son; indeed, the action is somewhat contrary to the revealed character, as this politician has clearly shown himself to be a man fully in control of his impulses, well aware of the appearance of his actions, in addition to understanding the fact that he was fully under observation. Again, an example of poor writing control.
I would not wish to imply, however, that the book is not enjoyable; i did like it, as i always do Francis' novels, just with a slight frisson of sadness that it wasn't quite up to the high standards he had set previously.