Tips and Tricks for Junior Detectives by Thomas Brezina
Book Review
Tips & Tricks for Junior Detectives
Age 9-12
In terms of solid "how to" information, this is the best of the detective books I've seen. Some of it could even be life saving - how to make a life raft out of your pants, how to lose a pursuer in a crowd.
The tips on codes and secret messages go beyond the usual letter-substitution codes - for example, you can write your actual message in really tiny letters, hidden under the stamp on an envelope. Your partner knows to ignore the letter in the envelope and remove the stamp (by dipping it in water) to see the secret message.
There's also an introduction to reading tracks, finger spelling, lip reading, and tons of other handy skills. There are a lot of privacy protection tricks, along with ideas right out of the movies - cutting a small hole in your newspaper to observe someone without being seen. A great book for kids who like a mix of practicality and intrigue in their fantasy play.