The moral of this story, set in the 21st century, is that freedom has to be won and kept by the young. It won the "Guardian" Prize for Children's Literature.
- ISBN10 0435121766
- ISBN13 9780435121761
- Publish Date 17 September 1973 (first published 1 March 1972)
- Publish Status Active
- Out of Print 7 September 2017
- Publish Country GB
- Publisher Pearson Education Limited
- Imprint Heinemann
- Format Hardcover
- Pages 160
- Language English