From Booklist
Gr. 2^-4. The fifth mystery about the Invisible Inc. trio has the three grade-school friends suspecting one of their own. The setting is karate class, with lots of talk about moves, punches, and blocks; but who has stolen Justin's karate belt? Is it his friend Charlene, who is mad at him? Justin is hard of hearing, and the way he copes with his disability is a natural part of the story. The teacher, Sensei Bobby, is encouraging but never condescending, demanding the highest performance from all of them. In the end, the friends find the shamefaced culprit, and order is restored. This is an advanced title in the Hello Readers series, and much of the story is told in dialogue, which may make it less an easy-reading title than a good drama for readers' theater in the classroom.
Hazel Rochman