This is not only a well-done mystery but it is also a fine indictment of a certain kind of chicanery, one that drives me particularly crazy.
I didn't warm to this at first because Brookmyre does an excellent job of suggesting that the reader is going to learn how real psych phenomena truly is. In the first chapters, I was actually getting frustrated, which just goes to show you the excellent job he does.
But the result is a damning indictment of psychics and mediums which is both engaging and funny. It's full of well-executed plot twists and only one or two groaning moments (including an absolutely terrible line in the last chapter).
And, in addition to this, Brookmyre ties his subject in with an attack on Neo-Conservatism, a fascinating link which I had not perceived myself, but one which I want to investigate further - the same credulity that allows for mystics allows for Neo-Conservative and other nonsense ideologies.
Anyway, just great stuff.