A Sixteen-year-old Progidy uses his mentor's invention to go into the past to exorcise his unreturned love for a beautiful girl, and discovers a mystery involving another of the professor's inventions.
- ISBN10 0689504292
- ISBN13 9780689504297
- Publish Date 31 October 1987
- Publish Status Out of Print
- Out of Print 11 December 2011
- Publish Country US
- Publisher Simon & Schuster
- Imprint Atheneum Books for Young Readers
- Format Hardcover
- Language English