After stumbling upon the secret society of ninja librarians who transcend time and space, Dorrie and her brother have officially become apprentices. They are determined to help the Lybrarians find a missing key that could destroy their beloved fortress, Petrarch's Library.
- ISBN13 9781492647935
- Publish Date 6 June 2017 (first published 1 January 2014)
- Publish Status Cancelled
- Publish Country US
- Imprint Sourcebooks, Inc
- Edition Reprint
- Format Paperback
- Pages 400
- Language English