Alien Secrets — Annette Curtis Klause

Puck, expelled from boarding school on Earth, is on her way to stay with her parents, who are doing alien research on Shoon.

On board Cat's Cradle, Puck befriends Hush, a native Shoowa, who is also returning to his home in shame. He was entrusted with a symbol of freedom for his people, and now that treasure has been stolen. He believes the Soo is hidden somewhere on Cat's Cradle.

Puck is determined to help discover the identity of the thief. But digging for the truth is very dangerous business -- especially when you're in the middle of an intergalactic journey.