I'm having such a busy week that I basically just picked the smallest book I could find in the local library! Also the title and definition of 'mentalist' at the beginning reminded me of the TV series of the same title
which I enjoy, though this isn't related other than having a main character who is a 'pyschic'.
Stage psychic Harry Gysel appears to predict the death of a woman in the audience. When she is found dead, Chief Inspector Morgan is brought in to investigate.
It was interesting reading this just after 'Confessions of a Conjuror
' since it involves some of the cold-reading and audience-manipulation tricks of the apparently mind-reading 'psychic' explained by Derren Brown