Your diamond tiara; your false teeth; your nervousness (there's even reference to another book for you to read if you're overanxious) particularly when you're not sure that Mr. Krotz's instruction is for real -- in spite of those elaborate diagrams. But if you're not a slouch you can construct secret compartments almost anywhere -- behind a spice rack or a door jamb or an electric outlet or a pilaster. (We have a place where we hide the money we lift from our husband's wallet -- it's called an oubliette.) Anyway, whether you're looking for security or entertainment, this is pleasant cache-as-cache-can entertainment, particularly for that handy man around the house.