The reader is invited to insert a cardboard key into a slot on each page and discover a surprising result on the following page.
- ISBN10 0448191040
- ISBN13 9780448191041
- Publish Date 9 November 1984
- Publish Status Out of Print
- Out of Print 13 March 2021
- Publish Country US
- Imprint Grosset & Dunlap
- Format Paperback (US Trade)
- Pages 20
- Language English