A mysterious postcard leads Lisa and Nilly from Oslo to Paris in search of Doctor Proctor but, once there, all they find of their missing friend is a time-traveling bathtub powered by a special soap and several sinister individuals determined to do all they can to locate the eccentric inventor.
- ISBN10 1416979751
- ISBN13 9781416979753
- Publish Date 15 November 2011 (first published 4 January 2011)
- Publish Status Active
- Publish Country US
- Imprint Simon & Schuster
- Edition Reprint ed.
- Format Paperback (US Trade)
- Pages 448
- Language English