This was a perfect mystery novel and I seriously don't understand why it's rated so low. As a mathematician, I loved the characterization of the 7 fundamental types of murder mysteries with beautiful examples. However the tension builds as Julia begins to suspect that Grant is withholding information from her and the audience is left to wait as they launch into another short story. While I didn't find Grant to be very compelling, it was so nice to read a compilation of solid murder mysteries within this framework.