These books have been outstanding, but just as in a TV series it must be very difficult to maintain consistent quality over time. This most recent novel has a plot that revolves around a character with multiple personalities. This phenomenon is so rare that some authorities believe that it doesn't actually occur, and my credulity maintenance facility was strained to breaking by this cheap gimmick. Furthermore, the snappy dialogue of previous IQ encounters seems lacking. The series may have jumped the shark, and I had to quit early to cut my loses.