Book excerpt: Filled with wacky whodunits and mini-thrillers,30 Second Mysteriesare the perfect quickies for the armchair gumshoe. Sample puzzle: Michael is fleeing a stampeding herd of buffalo when he comes to a wide, deep river. To escape, he must cross it, but there is no bridge, and he has no boat or materials to make a boat. He cannot even swim. Nonetheless, he easily gets away. The “mystery” is how Michael can cross the river without being followed by the buffalo. This book contains a total of 400 fun head-scratchers.