When Markham Crewe took the job of social secretary for Andrew Harrison he had no idea how actually unpleasant the man could be, but it was a well-paying job with some advantages. Then Andrew Harrison goes missing and after he is found, he is killed, on a boat, in a locked room.
At first everyone believes that it's a natural death but after a while they realise that it's not but it is an unusual death with a lot of cunning. Finding out the solution would take all Inspector French's cunning.
There were times when I did some guessing but at no stage did I get all the pieces together. Clever and interesting but I was a little sceptical about the method. ( )