Lawrence Treat, author of many puzzle books and pioneer of 'police procedurals' of this sort, created two books for this fun children's series - both containing over 20 well thought out visual puzzles inside.

Each books artwork is illustrated in simple black and white linework, usually with a 'before and after' scene, with slight differences that hide clues to the puzzle. These usually aren't 'spot the difference' per se, but moreso illustrate a passage of time, with something occuring inbetween. Text is minimal on each page - usually only 2-3 paragraphs given more focus to the images themselves and breaks the fourth wall about the 'drawings' containing a conundrum.

Puzzles are pleasingly unique with some solutions genuinely difficult and hard to find, without being unreachable for readers.

From reviews of this series, like a lot of Treat's work, these are clever and well-packaged mysteries for a younger crowd, and are a good addition to Treat's career, sadly passing shortly after these were published in 1998.