Invisible Inc.

When someone takes Justin's karate belt, his friends in Invisible Inc. try to determine a motive as they investigate the mystery.

Chip, an invisible boy, and his friends solve the mystery of who took the school ball from the playground.

Charlene's story is voted best in the class, but when she goes to read it at Parents' Night, it has vanished from her folder.

The Invisible Inc. gang makes computer greeting cards to raise money to invite an author to school, and solves the mystery of the author's real name.

The invisible boy Chip intends to enter his invisible dog Max in the dog show, but when Max comes up missing, Chip and his Invisible Inc. friends suspect foul play.

Chip, an invisible boy, and his friends investigate the mysterious disappearance of yogurt-covered raisins, mixed nuts, and ginger snaps from their classroom.

The Invisible Inc. gang makes computer greeting cards to raise money to invite an author to school, and solves the mystery of the author's real name.