In such puzzle-stories as "The Evidence on the Japanned Box," "The Toledo Death Threat," and "The Huppheimer Museum Robbery," Wren and McKay sparked a craze for "ten-minute mysteries" that spread through the American pulp-detective magazines of the late 1920s.
These are the originals - and perhaps the most perfect examples - of the mystery puzzle book.

In words, charts, and diagrams, you are placed at the crime scene and presented with facts established by the police.

What do you observe?
Which are the telltale clues?
Where are the red herrings?

Each crime is scored to a degree of difficulty, with a perfect score of ten points per puzzle. And if you find you are stumped, you can turn to the back of the book, where the answers are printed (but upside-down, to deter you from giving up too easily).

Don't cheat: you'll only spoil the fun.