The Hidden (Animorphs, Book 39)
By K. A. Applegate.
Description
The Yeerks plan to use the Helmacron ship they have repaired to capture the Andalites and track down Elfangor's blue cube--the cube that gives Cassie, and the other animorphs the ability to morph. - from Amzon
ISBN(s)
0439106788, 9780439106788
