Novel Unit for Hide & Seek by Katy Grant written by Sarah Pennington. This is a great compliment to Hide and Seek by Katy Grant. Available on Amazon. http://www.amazon.com/Novel-Unit-Hide-Seek-Grant/dp/1479156078/ref=sr_1_2?ie=UTF8&qid=1365445563&sr=8-2&keywords=hide+and+seek+katy+grant