Bright siblings-and amateur inventors-Nick and Tesla Holt are back in this fourth instalment. With the mystery of the spy's identity solved, the kids face a whole new crop of questions about their parents' mysterious disappearance. To unravel the mystery, they'll have to come up with all-new cyborg gadgets together with their zany scientist Uncle Newt and their friends Silas and DeMarco.
- ISBN10 1594747296
- ISBN13 9781594747298
- Publish Date 7 October 2014 (first published 1 January 2014)
- Publish Status Active
- Out of Print 2 March 2016
- Publish Country US
- Imprint Quirk Books
- Format Hardcover
- Pages 272
- Language English
- URL https://penguinrandomhouse.com/books/isbn/9781594747298