Dr. Drabble's Amazing Invisibility Mirror(1992)
(The seventh book in the Dr. Drabble Genius Inventor series)
A novel by Sigmund Brouwer
PJ and Chelsea are going around the world with their missionary parents and Dr. Drabble's brilliant all-in-one traveling apparatus. Dr. Drabble has invented a mirror that makes PJ and Chelsea invisible- and they trot off tho explore Japan? But they soon discover that being invisible has its drawbacks, and realize that taking without paying is always wrong.
Used availability for Sigmund Brouwer's Dr. Drabble's Amazing Invisibility Mirror
March 1992 : USA Hardback